Computer Networks: Types, Topology, and Internet Essentials

Posted on Jan 30, 2026 in Marketing

Computer Networks: Fundamentals and Resource Sharing

A computer network is a system of interconnected computers and other devices that communicate and share resources. Networks allow data and information to be exchanged efficiently among connected devices.

Local Area Network (LAN)

A Local Area Network (LAN) connects computers and devices within a limited geographic area, such as a home, office, or building. LANs offer high data transfer speeds (ranging from 10 Mbps to 1 Gbps or higher), enabling fast communication and resource sharing like files, printers, and internet access among devices in the network. LANs typically use Ethernet cables or Wi-Fi for connections and employ networking devices like switches, routers, and access points. The limited geographic scope allows LANs to maintain high security and control over data access.

Wide Area Network (WAN)

A Wide Area Network (WAN) covers a larger geographic area, linking multiple LANs over cities, countries, or even globally. WANs often use leased telecommunication lines or satellite links for communication and generally have slower data transfer speeds than LANs due to the larger distances involved. The Internet is the largest example of a WAN.

Network Topology Arrangements

Network topology refers to the layout or arrangement of devices and connections in a network. Common network topologies include:

  • Star topology: All devices connect to a central switch or hub, which manages data traffic.
  • Bus topology: Devices share a single communication line or bus to send and receive data.
  • Ring topology: Devices form a closed loop or ring where data travels in one direction until reaching its destination.
  • Mesh topology: Devices connect directly to multiple other devices, offering high redundancy and reliability.

The Internet: Global Connectivity and Applications

The Internet is a global network of interconnected computers and devices that enables communication, data exchange, and access to a vast range of information and services across the world. It functions as the backbone infrastructure for many digital applications and has transformed communication, business, education, entertainment, and daily life.

Applications of the Internet

The applications of the Internet are diverse and include:

  • Communication: Email, instant messaging apps like WhatsApp, video conferencing tools like Zoom, Google Meet, and Skype enable real-time interaction regardless of location.
  • Web Browsing: Access to billions of web pages providing information, entertainment, news, and much more through web browsers.
  • E-Commerce: Online shopping platforms such as Amazon and Flipkart allow buying and selling products globally with convenient payment options.
  • Online Banking and Digital Payments: Internet banking and payment apps like Paytm, Google Pay facilitate cashless financial transactions safely and quickly.
  • Social Networking: Platforms like Facebook, Instagram, Twitter, and LinkedIn connect people socially and professionally.
  • Education: E-learning platforms and online courses make education accessible remotely.
  • Entertainment: Streaming services like Netflix, YouTube provide on-demand movies, music, and videos.
  • Research and Information Sharing: Researchers share papers and data globally while users can access a wealth of knowledge.
  • Stock Market Updates and Trading: Real-time market data and trading capabilities are available online to investors.

Website Addresses (URLs)

A Website Address, also known as a URL (Uniform Resource Locator), is the unique address used to access a specific website or resource on the Internet. It usually starts with “http://” or “https://” indicating the protocol, followed by the domain name (e.g., www.example.com) which identifies the website, and may include a path to a specific page or file within the website. URLs help web browsers locate web resources quickly and accurately.

Popular Web Browsers in 2025

Popular web browsers in 2025 include:

  • Safari: Leading in speed and graphics performance, especially optimized for Apple devices.
  • Google Chrome: Known for its broad compatibility, extensive extension library, and standards compliance.
  • Microsoft Edge: Offers strong productivity features, AI integration, and seamless Microsoft 365 connectivity.
  • Mozilla Firefox: Popular for privacy-focused browsing with strong tracking protection.
  • Brave: Known for built-in ad and tracker blocking with a focus on privacy.
  • Opera and Vivaldi: Niche browsers with unique features such as built-in VPN, customization, and split-screen tab views.

Among these, Safari is currently ranked the fastest and most energy-efficient overall, while Chrome remains the most widely used and extensible browser. Firefox and Brave are favored for privacy, and Edge excels in productivity features.[1][2][3][4]

Web Browser Market Share (2025 Estimates)

Popular Web Browsers in 2025 are:

  • Google Chrome: Dominates with over 70% global market share, popular for speed, extension support, and compatibility.
  • Apple Safari: Holds around 14-18%, preferred on macOS and iOS devices for optimized performance.
  • Microsoft Edge: Commands about 5%, integrates well with Windows and Microsoft 365 ecosystem.
  • Mozilla Firefox: Has roughly 2-3%, known for privacy features and open-source nature.
  • Opera: Maintains a small share near 2%, offering features like built-in VPN and ad blocking.
  • Samsung Internet is also notable on mobile devices with a small share.

Popular Search Engines

Popular Search Engines:

  • Google: The leading search engine globally with the largest index and most sophisticated algorithms.
  • Bing: Microsoft’s search engine integrated with Edge and Windows.
  • Yahoo: A traditional major player still used by many.
  • DuckDuckGo: Popular for privacy-focused search without tracking.
  • Baidu: Dominant in China.
  • Yandex: Leading Russian search engine.

Searching on the Internet involves using search engines to find information by typing keywords or queries into a search box. The search engine crawls and indexes web pages then returns relevant results ranked by algorithms based on relevance, authority, and user signals. Users can refine searches with operators and use features like voice search or image search for more precise results.

Email (Electronic Mail) Communication

Email (electronic mail) is a digital communication system that enables users to send, receive, and manage messages over the Internet quickly and efficiently. It has become a fundamental tool in both personal and professional communication.

Using Emails

Using Emails involves having an email account which serves as a digital address (e.g., user@example.com). To start using email, one must first open or create an email account through providers like Gmail, Outlook, Yahoo Mail, or others by signing up with personal details and creating login credentials.

The Email Mailbox Structure

The Mailbox in an email account typically consists of folders such as Inbox and Outbox. The Inbox stores incoming emails that have been received, while the Outbox temporarily holds emails that are in the process of being sent or waiting for a connection to send.

Creating and Sending a New Email

Creating and Sending a New Email includes:

  • Clicking on “Compose” or “New Email” button.
  • Entering recipient email addresses in the “To” field.
  • Adding additional recipients in “Cc” (carbon copy) or “Bcc” (blind carbon copy) fields if needed.
  • Writing the subject line summarizing the email topic.
  • Typing the message in the body area.
  • Optionally attaching files like documents, images, or spreadsheets.
  • Finally, clicking the “Send” button to deliver the email.

Replying to an Email Message involves opening a received email and clicking “Reply” or “Reply All” to send a response back to the sender or all recipients.

Forwarding an Email Message lets the user send a received email to a new recipient by clicking “Forward,” entering a new email address, and optionally adding comments before sending.

Searching Emails within a mailbox is useful for locating specific messages using keywords, sender names, subjects, or dates through the email client’s search feature.

Attaching Files with Email is done by clicking the attachment clip icon during email composition, selecting files from the device, and uploading them to the email.

Email Signature Importance

An Email Signature is a personalized block of text or images automatically appended at the end of outgoing emails. It typically includes the sender’s name, job title, company, contact information, and sometimes legal disclaimers or promotional content. Email signatures add professionalism and provide recipients with essential contact details without typing them repeatedly.

These features collectively make email an effective communication method, enabling clear, organized, and quick correspondence across the globe. Most modern email clients and webmail services offer intuitive interfaces to perform all these tasks seamlessly. This robust tool supports attachments, automatic replies, filtering, and advanced searching to enhance productivity and communication [drawing from general tech knowledge].

Social Networking and Instant Messaging

Social Networking refers to platforms that allow users to build communities and connect with others based on shared interests or relationships. Instant Messaging (IM) focuses on real-time, synchronous, private communication. While they overlap (most social networks have IM features), their primary focus differs.

Key Social Networking Platforms

These platforms focus on different types of content and connections:

  1. Facebook (Meta) :Facebook is the largest general social networking site, designed primarily for connecting friends and family. Users create profiles, share multimedia content (photos, videos), post status updates, and engage through features like the News Feed, Groups (for niche communities), and Events. It serves as a comprehensive hub for personal, community, and business engagement.
  2. Twitter (X) :Twitter, now rebranded as X, is a micro-blogging platform that emphasizes short-form content (text posts or “Tweets”) and real-time information sharing. It is widely used for following news, public figures, and participating in global public conversations driven by Hashtags and trending topics. Its primary utility is rapid dissemination and reaction to current events.
  3. LinkedIn :LinkedIn is the leading professional networking site. Its focus is strictly on career development and business connections. Users create detailed profiles that serve as digital resumes, share industry news, and network with colleagues, recruiters, and companies. It is the go-to platform for job searching, B2B (Business-to-Business) interactions, and building a professional personal brand.
  4. Instagram (Meta) :Instagram is centered around visual storytelling. Its primary content forms are Photos and short Videos (Reels), often focusing on aesthetic appeal, lifestyle, and visual branding. Features like Stories (ephemeral, 24-hour content) and Direct Messages (DMs) facilitate engagement, making it hugely popular with creators, influencers, and brands focusing on consumer engagement (B2C).

Instant Messaging (IM) Platforms

IM applications enable real-time, one-on-one or group text-based communication, often with integrated voice and video calls.

  • WhatsApp (Meta) :WhatsApp is the world’s most popular messaging app, known for its simplicity and default End-to-End Encryption (E2EE) for all messages and calls, ensuring high privacy between the sender and receiver. It is primarily tied to the user’s phone number and is widely used for intimate personal and small business communication globally.
  • Facebook Messenger:Messenger is the instant messaging extension of the Facebook ecosystem. While it can be used independently, its strength lies in its integration with a user’s Facebook social graph. It is convenient for communicating with your existing Facebook connections and supports standard features like text, voice/video calls, and file sharing.
  • Telegram:Telegram is known for its strong focus on speed, security, and power-user features. Unlike WhatsApp, its chats are cloud-based by default (allowing independent access from multiple devices), and it offers large Group limits (up to 200,000 members) and Channels for broadcasting to unlimited subscribers. It features optional E2EE through “Secret Chats” and allows users to share much larger files (up to 2GB per file) than other platforms.