Computer Networks


The need of  being connected 


To share information with other computers, such as an external computer, our computer must be connected to them. We can do this in two steps. 

First, we connect the computer to a very large and powerful computer called Server. The server can store a lot of data and expensive software. Expensive hardware devices can also be connected to it so we can share data, software, and hardware with other computers connected to the server.


Networks


A network is comprised of multiple people or devices connected to each other. Your friends are circles. You share your happiness and problems with them. A computer network is a network of two computerized computer and hardware devices with viruses. A computer network will contain some other important parts.





The Sending Ddevice


A sending device sends data over a network. When a computer needs to use a printer or a program on a server, it sends a request to the server. This computer is a sending device.



The receiving device 


A receiving device receives data or signals sent by the sending device. In the previous example, the intensity is the device.


The transmission medium


A transmission media connects the computer to the two-to-two conn. It signals from a sending device to a receiving device. Telephones and computers have two connecting wires or wired media transmission media There are three main types of cables.

The erotic cable is one of the simplest types. It consists of a cruiser-made moving wire. Signals travel along the coil wire, insulated with a layer of insulation material inside the wire. This prevents the signal from being blocked. From. Occasionally, signals from one cable may interfere with the other's signal. This is called the crosstalk.


The twisted cable consists of two wires that twist around each other. This cruise reduces stacks and other problems, thicker cable is more thick and flexible.


Fiber optic cables carry data faster than other types of cables. Fiber optic cables are made of glass fibers, the wire signals travel across the inner surface of the wire.


The communication device


A communication device helps two devices understand each other. We find that the digital signals that flow into a computer are different from the analog signals along the telephone wires, the digital signals cannot travel along the telephone lines and the computers do not understand the analog signals. The telephone does not travel along the lines and the computer cannot understand the analog signals.

A communication device converts digital signals into analog signals and vice versa. The communication device used in a computer is called a modem.

Network card or network interface card

A computer must have a special processing capability to be part of the network. We can enhance computer processing capabilities by connecting the advanced card to the motherboard. An extension card that allows a computer to connect to a network is called a network card.


The computer network


A computer network is a group of computers connected to each other through a transmission medium. Computers can share data, programs, and hardware devices when they are part of a network. A child is said to be a single computer.


The hub


A hub connects all computers to the network with two conn. All computers are connected to the cable hub. When a computer sends a message to another computer, the message is first sent to the hub. The hub then sends signals to all computers on the network. This is a problem because not every computer needs a message, even a hub is called a repeater.



The switch 


A switch is better than a hub. A switch computer brings up the address of each computer on the network. When the signal from the sending device reaches the switch, it sends the message only to the computer that needs the message.


The router


A router helps us send messages from one network to another. A router connects two networks to two conn. When a message reaches a router, the first router identifies the recipient's computer network. It then sends a message to the recipient computer's address on that network.


Types of computer networks 

There are many types of computer networks.


Peer- to peer network


In a peer-to-peer network, there is no central computer or server. Each computer is connected to another computer and no computer is more important than the other.

A local area network (LAN) connects computers in the same building. All the people who need to share information work in the same room or building. LANs are found in schools, colleges, and offices.


Metropolitan area network (MAN) 


A Metropolitan Area Network (MAN) combines two or more LANs. It connects computers in different parts of a city. It is larger and faster than a LAN. It is also more expensive


Wide area network (wan) 


A wide area network (WAN) combines many LANs and MANs. It connects computers in different cities or areas. A WAN is larger than a MAN. It uses a lot of cables. Satellite connections are faster, but they are very expensive.

We will now discuss some special types of networks.


The internet 


The Internet is a special kind of van. It can link up to all LANs. A worldwide network of arcsec. The Internet uses a large and powerful server.


The intranet 


Provides two conn to computers within an Internet office. It doesn't just link two computers to one building. It gives computers two conn in different cities. Internet uses Internet technology. It's faster than a LAN or WAN and can carry more data. But it does not combine different lenses. It is a single network.