Understanding Computer Networks and the Internet
Internet allows access to all information and causes changes in the experience and the very perception of space and time. These changes make the emergence of new forms of culture.
A computer is an electronic machine that processes data in accordance with the advice given by a program stored in its memory. It consists of hardware and software.
A network is a collection of computers that are connected to each other to share resources and information.
You can connect to a network via wired (network interface card for computer and server computer) or if the network is at a distance by telephone.
To transmit information, computers use electrical signals are called digital, which represent the info. Magnitudes through discrete or discontinuous.
The 1 and 0 are part of binary numbers. The name given to each one of them bit. Any character or letter equivalent to 8 bits (8 bits = 1 byte)
The telephone line, transmitting information through electrical signals that are called analogue. An analog signal is one whose intensity or frequency is directly proportional to the data it represents.
The code uses a computer is different from the telephone line, so you need to convert the data to it using a modem.
The modem allows translation from one code to another, performs 2 actions modulation and demodulation.
When the modem receives digital data and analog must pass to be carried by telephone line performs modulation.
When the process is backwards (coming from the telephone line and go to the pc) performs the demodulation. The speed with which a transmitting modem is measured in bits per second (bps).
A server is a computer that distributes the data it receives to each of the machines on the network, is responsible for regulating the traffic of information flowing through computers, always present in a network.
Internet is the great set of networks to which you are adding new ones.
In the process of network communication, the program is called a client that is in the machine of the person requesting information and the application server interprets the request in the requesting computer. Then the networks are client / server architecture.
One of the conditions to be satisfied before a message can reach one of the computers connected to the network is to take direction. The address is set by a combination of 4 numbers from 0 to 225. So that users do not have trouble remembering the address was elaborated a system called DNS or Domain Name System by what it does is translate the names. EJ: altocity.Com
A domain is a logical grouping of computers. The grouping is logical and not physical because the computers that make up a single domain does not have to share the same physical space.
Information, to circulate faster divided into packets, each “weighs” 576 bytes of information and consists of:
* The data transmitted
* The address of the person who issued
* The address of the recipient
* A checker that verifies that all good
But sometimes the computers are different, so they respond to different code, for that is I think a language with common rules. Rules or codes that enable communication between different computers are called protocols, and the Internet is called TCP / IP (Transmission Control Protocol / Internet Protocol)
E-mail or e-mail was one of the first Internet services and remains the most popular. It is almost the same as the mail, nothing more than one computer to another, send messages which can contain any kind of information: text, images, graphics, etc. Etc.
Each user has an address associated to any other user of the network has, so that the communication is unmistakable.
Mailing lists arose when people were connected by the middle seeking extensive discussions between them, so they formed groups to support them. Operate on the basis of the notification by mail, except that if someone sends an email, gets the whole group and not 1 of the recipients.
The web
Called WWW (World Wide Web)
Meaning WEB OF GLOBAL.
Following the expansion of the network the information was such that it was not easy to find what was sought as a Swede decided to create a tool that helped to organize the information combianaba text, graphics, videos and sounds on pages and sites easily go and comfort.
3 Important:
MULTIMEDIA:
a combination of text, images, photos, audio, sound, animation, video and any other data in digital form.
Hypertext in the area of the Web is an electronic document in which there are links or connections between words or groups of words.
HYPERMEDIA:
a document that combines elements of multimedia with hypertext elements.
On the Web, information is organized in units called sites, a set of pages of an organization or an individual. The main page of each site has a welcome message and menu information generla called home page.
The action of moving through different pages is called browsing.
The pages are usually connected by means of links or connections. These links are electronic connections.
The user has two ways to search the web in so-called Seekers, you can find everything available in relation to a topic, getting into subject directories or search using keywords.