Essential Concepts in Network Topologies, Protocols, and Data Transmission

Posted on Jan 29, 2026 in Computers

Primary Network Topologies

Network Topologies describe the physical or logical arrangement of nodes (devices) and their connections within a network. They define how devices are interconnected and communicate with each other.

Factors Affecting Network Topology Selection

• Scalability: The ability to expand the network easily influences the choice of topology. For example, star and tree topologies are more scalable because additional devices can be added without disrupting the existing network. In contrast, bus topologies can become problematic as the number of devices increases, potentially leading to congestion and performance issues.

• Performance: The efficiency and speed of data transmission can vary with topology. Star topologies typically offer better performance because each device has a dedicated connection to the central hub, reducing the risk of data collisions. In contrast, bus and ring topologies can suffer from performance degradation as the number of devices increases, due to increased traffic or potential bottlenecks.

• Fault Tolerance: The network’s ability to withstand and recover from failures is critical. Mesh topologies provide high fault tolerance as they offer multiple paths for data transmission, ensuring that if one path fails, others can take over. Conversely, bus topologies are less fault-tolerant because a failure in the central cable can disrupt the entire network.

• Network Traffic: The amount and type of network traffic influence topology selection. Star and mesh topologies handle high traffic volumes better due to their multiple connections and paths. Bus and ring topologies can struggle with high traffic as they rely on fewer pathways for data transfer, leading to potential congestion.

• Security: The level of network security required can affect the choice of topology. Mesh topologies offer higher security as they provide multiple pathways and reduce the risk of single points of failure. Star topologies also offer reasonable security by centralizing network management, while bus topologies may have vulnerabilities due to the single central cable that can be a target for attacks.

Bus Topology

A data network with a bus topology has a linear transmission cable, usually coaxial, to which many network devices and workstations are attached along the length. The server is typically at one end of the bus. When a workstation has to send data, it transmits packets with the destination address in its header along the bus.

The data travels in both directions along the bus. When the destination terminal sees the data, it copies it to the local disk.

Advantages of Bus Topology

• Easy to install and maintain
• Can be extended easily
• Very reliable because of single transmission line

Disadvantages of Bus Topology

• Troubleshooting is difficult as there is no single point of control
• One faulty node can bring the whole network down
• Dumb terminals cannot be connected to the bus

Ring Topology

In a ring topology, each terminal is connected to exactly two nodes, giving the network a circular shape. Data travels in only one pre-determined direction.

When a terminal has to send data, it transmits it to the neighboring node which transmits it to the next one. Before further transmission, data may be amplified. In this way, data traverses the network and reaches the destination node, which removes it from the network. If the data reaches the sender, the sender removes the data and resends it later.

Advantages of Ring Topology

• Small cable segments are needed to connect two nodes
• Ideal for optical fibers as data travels in only one direction
• Very high transmission speeds possible

Disadvantages of Ring Topology

• Failure of a single node brings down the whole network
• Troubleshooting is difficult as many nodes may have to be inspected before the faulty one is identified
• Difficult to remove one or more nodes while keeping the rest of the network intact

Star Topology

In a star topology, the server is connected to each node individually. The server is also called the central node. Any exchange of data between two nodes must take place through the server. It is the most popular topology for information and voice networks as the central node can process data received from the source node before sending it to the destination node.

Advantages of Star Topology

• Failure of one node does not affect the network
• Troubleshooting is easy as a faulty node can be detected from the central node immediately
• Simple access protocols required as one of the communicating nodes is always the central node

Disadvantages of Star Topology

• Long cables may be required to connect each node to the server
• Failure of the central node brings down the whole network

Tree Topology

Tree topology has a group of star networks connected to a linear bus backbone cable. It incorporates features of both star and bus topologies. Tree topology is also called hierarchical topology.

Advantages of Tree Topology

• Existing network can be easily expanded
• Point-to-point wiring for individual segments means easier installation and maintenance
• Well suited for temporary networks

Disadvantages of Tree Topology

• Technical expertise required to configure and wire tree topology
• Failure of the backbone cable brings down the entire network
• Insecure network
• Maintenance is difficult for large networks

Analog and Digital Signals

Analog and digital are the different forms of signals used to carry information from one device to another. An analog signal is a continuous wave that keeps on changing over a time period. A digital signal is discrete in nature. The fundamental difference is that the analog signal is typically represented by sine waves, whereas the digital signal is represented by square waves.

Analog Signal Characteristics

An analog signal is a kind of continuous waveform that changes over time. An analog signal is further classified into simple and composite signals. A simple analog signal is a sine wave that cannot be decomposed further. On the other hand, a composite analog signal can be further decomposed into multiple sine waves. An analog signal is described using amplitude, period or frequency, and phase. Amplitude marks the maximum height of the signal. Frequency marks the rate at which the signal is changing. Phase marks the position of the wave with respect to time zero.

(Diagram)

An analog signal is not immune to noise; hence, it faces distortion and decreases the quality of transmission. The range of values in an analog signal is not fixed.

Digital Signal Characteristics

Digital signals also carry information like analog signals but are somewhat different. A digital signal is a noncontinuous, discrete time signal. A digital signal carries information or data in the binary form, meaning it represents information in the form of bits.

A digital signal can be further decomposed into simple sine waves that are called harmonics. Each simple wave has different amplitude, frequency, and phase. A digital signal is described with bit rate and bit interval. Bit interval describes the time required for sending a single bit. On the other hand, bit rate describes the frequency of the bit interval.

(Diagram)

A digital signal is more immune to noise; hence, it hardly faces any distortion. Digital signals are easier to transmit and are more reliable when compared to analog signals. A digital signal has a finite range of values and consists of 0s and 1s.

Analog and Digital Transmission

Analog Transmission Concepts

To send digital data over an analog medium, it needs to be converted into an analog signal. There can be two cases according to data formatting:

• Bandpass: Filters are used to filter and pass frequencies of interest. A bandpass is a band of frequencies which can pass the filter.

• Low-pass: A low-pass is a filter that passes low frequencies signals.

When digital data is converted into a bandpass analog signal, it is called digital-to-analog conversion. When a low-pass analog signal is converted into a bandpass analog signal, it is called analog-to-analog conversion.

Digital-to-Analog Conversion (Modulation)

When data from one computer is sent to another via some analog carrier, it is first converted into analog signals. Analog signals are modified to reflect digital data.

An analog signal is characterized by its amplitude, frequency, and phase. There are three kinds of digital-to-analog conversions:

• Amplitude Shift Keying (ASK): In this conversion technique, the amplitude of the analog carrier signal is modified to reflect binary data. When binary data represents digit 1, the amplitude is held; otherwise, it is set to 0. Both frequency and phase remain the same as in the original carrier signal.

• Frequency Shift Keying (FSK): In this conversion technique, the frequency of the analog carrier signal is modified to reflect binary data. This technique uses two frequencies, f1 and f2. One of them, for example f1, is chosen to represent binary digit 1, and the other one is used to represent binary digit 0. Both amplitude and phase of the carrier wave are kept intact.

• Phase Shift Keying (PSK): In this conversion scheme, the phase of the original carrier signal is altered to reflect the binary data.

Digital Transmission and Line Coding

Data or information can be stored in two ways: analog and digital. For a computer to use the data, it must be in discrete digital form. Similar to data, signals can also be in analog and digital form. To transmit data digitally, it needs to be first converted to digital form.

Digital-to-Digital Conversion

This section explains how to convert digital data into digital signals. It can be done in two ways: line coding and block coding. For all communications, line coding is necessary, whereas block coding is optional.

Line Coding Schemes

The process for converting digital data into a digital signal is called Line Coding. Digital data is found in binary format and is represented (stored) internally as a series of 1s and 0s.

The digital signal is denoted by a discrete signal, which represents digital data. There are three types of line coding schemes available:

• Unipolar: Unipolar encoding schemes use a single voltage level to represent data. In this case, to represent binary 1, high voltage is transmitted, and to represent 0, no voltage is transmitted. It is also called Unipolar Non-Return-to-Zero (NRZ) because there is no rest condition; it either represents 1 or 0.

• Polar Encoding: Polar encoding schemes use multiple voltage levels to represent binary values. Polar encoding is available in four types:

  • Polar Non-Return to Zero (Polar NRZ): It uses two different voltage levels to represent binary values. Generally, positive voltage represents 1 and negative voltage represents 0. It is also NRZ because there is no rest condition.

The TCP/IP Networking Model

The TCP/IP model is a networking model used for communication over the internet. It has four layers, and each layer has specific functions to ensure data is transmitted properly between devices.

1. Application Layer

   • This is the topmost layer of the TCP/IP model.
   • It provides network services directly to users and applications.
   • Examples of services: HTTP (web browsing), FTP (file transfer), DNS (domain name system), SMTP (email).
   • It handles functions like data formatting, encryption, and session management.
   • The user interacts with this layer through applications.

2. Transport Layer

   • Responsible for end-to-end communication between devices.
   • Ensures that data is transmitted reliably and in the correct order.
   • Uses two main protocols:
     • TCP (Transmission Control Protocol): Reliable, connection-oriented (data is delivered without errors).
     • UDP (User Datagram Protocol): Faster, connectionless, used for applications like video/audio streaming.
   • Performs flow control, error control, and segmentation of data.

3. Internet Layer

   • Main function: Routing data packets across networks.
   • Decides the best path for data to travel from source to destination.
   • Uses IP (Internet Protocol) as the main protocol.
   • Other important protocols include ICMP (error reporting) and ARP (address resolution).
   • Breaks data into packets and adds IP addresses to each packet.

4. Network Access Layer (or Link Layer)

   • This is the lowest layer of TCP/IP.
   • Responsible for physical transmission of data over the network.
   • Includes protocols and hardware like Ethernet, Wi-Fi, NICs, LAN, and cables.
   • Handles framing, physical addressing (MAC address), and access to transmission media.
   • Ensures the data is placed on the physical network properly.

Key Features of the TCP/IP Model

• It is simple, flexible, and widely used in real-world networks.
• Supports interconnection of different types of networks.
• Provides end-to-end communication using IP addressing.
• Used as the foundation of the entire Internet.

Conclusion: The TCP/IP model is a four-layer networking model that explains how data travels from one device to another over the internet. Each layer performs specific tasks to ensure that communication is accurate, reliable, and efficient.

OSI Reference Model (Seven Layers)

The OSI (Open Systems Interconnection) model is a conceptual framework that explains how data is communicated over a network. It has seven layers, and each layer has a specific role in data transmission.

1. Physical Layer (Layer 1)

   • Deals with the physical transmission of raw bits over a medium.
   • Includes cables, switches, hubs, connectors, voltages, and signals.
   • Defines bit rate, physical topology, and transmission media.
   • Converts data into electrical, light, or radio signals.

2. Data Link Layer (Layer 2)

   • Ensures error-free data transfer between two directly connected devices.
   • Performs framing, error detection, error correction, and flow control.
   • Uses MAC addresses for physical addressing.
   • Divided into two sublayers:
     • LLC (Logical Link Control)
     • MAC (Media Access Control)

3. Network Layer (Layer 3)

   • Responsible for routing packets from source to destination across multiple networks.
   • Uses IP addressing and routing algorithms.
   • Handles packet forwarding, congestion control, and logical addressing.
   • Example protocols: IP, ICMP, RIP, OSPF.

4. Transport Layer (Layer 4)

   • Ensures reliable and orderly delivery of data.
   • Performs segmentation, flow control, and error control.
   • Provides end-to-end communication.
   • Uses protocols like:
     • TCP (reliable)
     • UDP (fast, connectionless)

5. Session Layer (Layer 5)

   • Manages and controls sessions (connections) between applications.
   • Responsible for session setup, maintenance, and termination.
   • Handles synchronization using checkpoints in long data transfers.
   • Allows communication between two devices to stay active.

6. Presentation Layer (Layer 6)

   • Deals with data translation, encryption, and compression.
   • Converts data into a form understandable by the application layer.
   • Ensures that data sent by the sender is readable by the receiver.
   • Examples: JPEG, MP3, encryption algorithms (SSL/TLS).

7. Application Layer (Layer 7)

   • The topmost layer, closest to the user.
   • Provides network services to applications.
   • Examples: HTTP, FTP, SMTP, DNS, Telnet.
   • Handles functions like file transfer, email, browsing, and remote login.

Key Features of the OSI Model

• Provides a standard framework for network communication.
• Helps in troubleshooting by isolating network issues layer-wise.
• Each layer performs a specific set of functions.
• Promotes interoperability between different devices and vendors.

Flow Control Mechanisms

Flow control is the management of data flow between computers or devices or between nodes in a network so that the data can be handled at an efficient pace. Too much data arriving before a device can handle it causes data overflow, meaning the data is either lost or must be retransmitted. For serial data transmission locally or in a network, the Xon/Xoff protocol can be used. For modem connections, either Xon/Xoff or CTS/RTS (Clear to Send/Ready to Send) commands can be used to control data flow.

Flow control is the mechanism that ensures the rate at which a sender is transmitting is in proportion with the receiver’s receiving capabilities.

Flow control is utilized in data communications to manage the flow of data/packets among two different nodes, especially in cases where the sending device can send data much faster than the receiver can digest.

In a network, flow control can also be applied by refusing additional device connections until the flow of traffic has subsided.

Networks of any size have many different devices connected, and each device has unique data transmission parameters. For instance, a router is built to manage the routing of data, whereas a desktop, at the receiving end of that data, has far less sending/receiving ability.

These differences in sending/receiving abilities may lead to conflict if the sender starts transmitting data faster than the receiving node’s ability. To counteract this problem, flow control is used. This technique manages the flow of data between nodes, keeping the sending/receiving capabilities of both nodes as the primary concern.

Xon-Xoff is an example of a flow control protocol that synchronizes the sender with the receiver. It transmits a ‘transmit off’ signal when the receiver no longer has space in its buffer and a ‘transmit on’ signal when the receiver can resume taking data. Xon-Xoff works on asynchronous serial connections.

Network Protocols and Classification

There are various types of protocols that support a crucial role in communicating with different devices across the network. These are:

1. Transmission Control Protocol (TCP): TCP is a popular communication protocol used for communicating over a network. It divides any message into a series of packets that are sent from source to destination, where they are reassembled at the destination.
2. Internet Protocol (IP): IP is designed explicitly as an addressing protocol. It is mostly used with TCP. The IP addresses in packets help in routing them through different nodes in a network until they reach the destination system. TCP/IP is the most popular protocol connecting networks.
3. User Datagram Protocol (UDP): UDP is an alternative communication protocol to TCP, implemented primarily for creating loss-tolerating and low-latency linking between different applications.
4. Post Office Protocol (POP): POP3 is designed for receiving incoming emails.
5. Simple Mail Transfer Protocol (SMTP): SMTP is designed to send and distribute outgoing email.
6. File Transfer Protocol (FTP): FTP allows users to transfer files from one machine to another. Types of files may include program files, multimedia files, text files, and documents, etc.
7. Hypertext Transfer Protocol (HTTP): HTTP is designed for transferring hypertext among two or more systems. HTML tags are used for creating links. These links may be in any form, like text or images. HTTP is designed on Client-Server principles which allow a client system to establish a connection with the server machine for making a request. The server acknowledges the request initiated by the client and responds accordingly.
8. Hypertext Transfer Protocol Secure (HTTPS): HTTPS is a standard protocol to secure the communication between two computers, one using the browser and the other fetching data from a web server. HTTP is used for transferring data between the client browser (request) and the web server (response) in the hypertext format. HTTPS does the same, except that the transferring of data is done in an encrypted format. Thus, HTTPS thwarts hackers from interpretation or modification of data throughout the transfer of packets.
9. Telnet: Telnet is a set of rules designed for connecting one system with another. The connecting process here is termed as remote login. The system which requests the connection is the local computer, and the system which accepts the connection is the remote computer.
10. Gopher: Gopher is a collection of rules implemented for searching, retrieving, as well as displaying documents from isolated sites. Gopher also works on the client/server principle.

Co-Functioning Protocols

Some other popular protocols act as co-functioning protocols associated with these primary protocols for core functioning. These are:

1. ARP (Address Resolution Protocol)
2. DHCP (Dynamic Host Configuration Protocol)
3. IMAP4 (Internet Message Access Protocol)
4. SIP (Session Initiation Protocol)
5. RTP (Real-Time Transport Protocol)
6. RLP (Resource Location Protocol)
7. L2TP (Layer Two Tunneling Protocol)
8. RAP (Route Access Protocol)
9. PPTP (Point To Point Tunneling Protocol)
10. SNMP (Simple Network Management Protocol)
11. TFTP (Trivial File Transfer Protocol)

Internet Service Providers (ISPs) and Access Methods

An Internet Service Provider (ISP) is an organization that provides access to the Internet.

Internet service providers can be either community-owned and non-profit, or privately owned and for-profit.

Types of ISPs

• Access ISPs: Directly connect clients to the Internet using copper wires, wireless, or fiber connections.
• Hosting ISPs: Lease server space for smaller businesses and other people (colocation).
• Transit ISPs: Provide large amounts of bandwidth for connecting hosting ISPs to access ISPs.

Internet Access Methods

Dial-up Internet Access

This is the oldest method of providing access to the Internet. It uses a telephone line to perform a modem-to-modem connection. For that purpose, the user’s computer is attached to a telephone line enabled modem device, which dials into the node of the ISP and starts transferring data between the servers that store websites the user wants to see and their Internet connected device.

DSL (Digital Subscriber Line)

DSL, short for ‘digital subscriber loop’ or ‘digital subscriber line’, is an advanced version of the dial-up Internet access method. In contrast to dial-up, DSL uses high frequency to execute a connection over the local telephone network.

Cable Internet

Cable Internet is among the most preferred methods for providing residential Internet access. Technically speaking, it represents a broadband Internet access method, using the high-bandwidth cable television network to transmit data between the global network and the households.

Wireless Broadband (WiBB)

This is a new-generation broadband Internet access technology, allowing the delivery of high-speed wireless Internet within a large area. Wireless broadband ISPs (WISPs) ensure connection speeds that come close to the wired broadband speeds provided by DSL and cable ISPs.

Wi-Fi Internet (Wireless Fidelity)

Wi-Fi (from Wireless Fidelity) has become one of the most widely distributed Internet access methods, with the growing usage of portable computers and Internet enabled mobile devices, such as smart phones, PDAs, game consoles, etc.

ISDN (Integrated Services Digital Network)

Another online data transmission method worth considering is ISDN or the Integrated Services Digital Network. ISDN represents a telephone system network, integrating a high-quality digital transmission of voice and data over the ordinary phone line.

Ethernet

Another Internet access type worth mentioning is Ethernet, the most widespread wired LAN (Local Area Network) technology, also used in wireless LANs. The Ethernet technology may ensure various speed levels.

Search Engine Functionality and SEO

A Search Engine is a service that allows Internet users to search for content via the World Wide Web (WWW). A user enters keywords or key phrases into a search engine and receives a list of Web content results in the form of websites, images, videos, or other online data.

The list of content returned via a search engine to a user is known as a Search Engine Results Page (SERP).

To simplify, think of a search engine as two components. First, a spider/web crawler trolls the web for content that is added to the search engine’s index. Then, when a user queries a search engine, relevant results are returned based on the search engine’s algorithm.

Early search engines were based largely on page content, but as websites learned to game the system, algorithms have become much more complex, and search results returned can be based on literally hundreds of variables.

There used to be a significant number of search engines with significant market share. Currently, Google and Microsoft’s Bing control the vast majority of the market. (While Yahoo generates many queries, their back-end search technology is outsourced to Microsoft).

Web search engines get their information by web crawling from site to site. The “spider” checks for the standard filename robots.txt, addressed to it. The robots.txt file contains directives for search spiders, telling it which pages to crawl. After checking for robots.txt and either finding it or not, the spider sends certain information back to be indexed depending on many factors, such as the titles, page content, JavaScript, Cascading Style Sheets (CSS), headings, or its metadata in HTML meta tags. After a certain number of pages crawled, amount of data indexed, or time spent on the website, the spider stops crawling and moves on.

Some websites are crawled exhaustively, while others are crawled only partially.

Indexing means associating words and other definable tokens found on web pages to their domain names and HTML-based fields. The associations are made in a public database, made available for web search queries. A query from a user can be a single word, multiple words, or a sentence. The index helps find information relating to the query as quickly as possible. Some of the techniques for indexing and caching are trade secrets, whereas web crawling is a straightforward process of visiting all sites on a systematic basis.

Between visits by the spider, the cached version of the page (some or all the content needed to render it) stored in the search engine working memory is quickly sent to an inquirer. If a visit is overdue, the search engine can just act as a web proxy instead. In this case, the page may differ from the search terms indexed. The cached page holds the appearance of the version whose words were previously indexed, so a cached version of a page can be useful to the website when the actual page has been lost, but this problem is also considered a mild form of linkrot.

Typically, when a user enters a query into a search engine, it is a few keywords.

Usenet Newsgroups and Netiquette

A newsgroup is an Internet-based discussion around an individual, entity, organization, or topic. Newsgroups enable remotely connected users to share, discuss, and learn about their topic of interest by exchanging text messages, images, videos, and other forms of digital content.

Newsgroups are also referred to as Usenet newsgroups.

Newsgroups were initially created in 1979 by some university students to exchange messages. Users can subscribe for free by submitting an email address, and the group generally consists of several topics/categories based around a main theme. The user/subscriber can post a message in a particular topic/category, which is either automatically visible in open newsgroups, or can only be viewed by approved members in moderated groups. All subscribers participating or following a particular topic/newsgroup will be notified of new messages and updates. Moreover, news/stories/topics in the newsgroup can be read through a downloadable news reader application.

Despite new technologies such as social media, newsgroups continue to thrive online.

How Usenet Newsgroups Work

When a newsreader such as Outlook Express connects to a news server, it downloads all the new messages posted in the subscribed newsgroup. We can either reply to a message after reading or post a news article to the news server.

The article posted to a news server is appended to the file maintained for that newsgroup. Then the news server shares the article with other news servers that are connected to it.

Then each news server compares if both carry the same newsgroup. If yes, then by comparing the files it checks if there are any new articles in the file; if so, they are appended to the file.

The updated file of the news servers is then sent to other news servers connected to it. This process continues until all of the news servers have updated information.

Reading and Subscribing to Articles

If a user wants to read an article, the user has to connect to the news server using the newsreader. The newsreader will then display a list of newsgroups available on the news server where the user can subscribe to any of the news groups. After subscription, the newsreader will automatically download articles from the newsgroup.

After reading the article, the user can either post a reply to the newsgroup or reply to the sender by email. The newsreader saves information about the subscribed newsgroups and articles read by the user in each group.

Posting an Article

In order to send a new article to a newsgroup, the user first needs to compose an article and specify the names of the newsgroups to whom he/she wants to send. An article can be sent to one or more newsgroups at a time, provided all the newsgroups are on the same news server.

It is also possible to cancel the article that you have posted, but if someone has downloaded an article before cancellation, then that person will be able to read the article.

Replying to an Article

After reading the article, the user can either post a reply to the newsgroup or reply to the sender by email. There are two options available: Reply and Reply group. Using Reply, the reply mail will be sent to the author of the article, while Reply group will send a reply to the whole newsgroup.

Cancelling an Article

To cancel an article after it is sent, select the message and click Message > Cancel message. It will cancel the message from the news server. But if someone has downloaded an article before cancellation, then that person will be able to read the article.

Usenet Netiquette Guidelines

While posting an article on a newsgroup, one should follow some rules of netiquette as listed below:

• Spend some time understanding a newsgroup when you join it for the first time.
• The article posted by you should be easy to read, concise, and grammatically correct.
• Information should be relevant to the article title.
• Don’t post the same article to multiple newsgroups.
• Avoid providing your business email address while subscribing to a newsgroup, as it may be used by spammers.
• Avoid using capital letters, as someone may interpret it as shouting.
• Prefer to use plain text wherever possible in your article.

Internet Uses and Core Terminology

The Internet has globally permeated everything we could imagine. There are hardly any people who do not rely on the Internet for their daily life. The uses of the Internet are endless; a few of them are as follows:

Key Uses of the Internet

• Education: The Internet is a valuable source for a lot of information. Data and information related to all fields are updated on the Internet. Students can spend a few minutes over the Internet to read their relevant study materials. Many students use the Internet for intense research on their projects.

• Communication: With the Internet, communication has become better and easier. One can call and talk to someone over the Internet. Video calls are an interesting option for communication through the Internet. Mailing is another form of communication, which is widely used in daily corporate life.

• Current Updates: Daily updates and current happenings are made available on the Internet instantly. The Internet is considered the real-time hub for all updates about politics, sports, entertainment, science, business, and many other fields.

• Corporate Base: The corporate world relies on the Internet for file sharing, data transfer, internal communication, external communication, and many other purposes. In simple words, the Internet forms the base of the corporate world today.

• E-Commerce: Other than using the Internet for business purposes, a business itself can be started and accomplished through the Internet. E-Commerce has many advantages, like reaching customers easily, giving a lot of information about the business, clearing customer queries instantly, and making payment also possible over the Internet.

Essential Internet Terminology

• World Wide Web (WWW): The World Wide Web (“WWW” or simply the “web”) is a collection of electronic documents (called web pages) that are linked together like a spider web. These documents are stored on computers called servers located around the world.

• Web Server: A Web Server is a computer that stores web pages. It is responsible for accepting request(s) from users and serves them with web pages. Two important web server programs are: IIS (Internet Information Services) and Apache, etc. Web servers are connected to the Internet 24 hours a day, seven days a week.

• Hyperlink: It is an element in an electronic document that links to another place in the same document or to an entirely different document or other resource. Hyperlinks usually appear as underlined text and in a different color, but they may also appear as graphics, such as buttons to click. Hyperlinks may be used to link another place in the same page, or another page, to play an audio or video file, to download a file, to set up a message to an e-mail address, and to link to other Internet resources.

• HTML (Hypertext Markup Language): It is a language that consists of certain keywords called ‘Tags’, used for writing the documents on the web.

• Web Page: A web page (such as the one you are looking at now) is an electronic document written in a computer language called HTML (Hypertext Markup Language). Web pages can contain text, graphics, video, animation, and sound, as well as interactive features, such as data entry forms. Each page has a unique address known as a URL (Uniform Resource Locator) that identifies its location on the server.