Computer Network is a large number of individual interconnected computers that serve organizations’ computational needs. In the earlier days, computer systems were highly centralized. There used to be one large computer system in a single large room of the organization. This room used to have glass walls that would allow visitors to gaze at this great electronic device.
As computers begin to evolve it became a challenge for organizations to merge computer systems in such a way that they could communicate and share information with each other. Fortunately, within some decades the old model of the single computer serving all of the organization’s computational needs was replaced by the model where a large number of individual interconnected computer systems do the job.
Let us get into more detail about the topic of computer networks. We will also go through the types of networks, their topologies, and their use. So, let’s begin.
- What is a Computer Network?
- How Many Types of Networks are There?
- Network Topology
- Uses of Computer Network
What is a Computer Network?
A computer network is a collection of a large number of autonomous computer systems interconnected by a single technology. Now when can we say that the two computer systems are interconnected?
Well, we can say that the two computer systems are interconnected when they are capable of exchanging information with each other. Now this connection or link between the computer can be of two types:
Wired Connection – For wired connection, we can use coaxial cable, twisted pair cable, and optical fiber.
Wireless Connection – For Wireless connection, we can use microwaves, communication satellites, cellular networks, radio waves, etc.
How Many Types of Networks are There?
The two general dimensions on which we can divide the types of networks are:
- Transmission Technology
If talk about transmission technology then it can be broadly classified into two types:
- Broadcast Links
- Point-to-Point Links
The point-to-point link connects individual pairs of machines. That means it exactly has one sender and one receiver. This is why we also call it unicasting.
In contrast in the broadcast link, the communication channel is shared by all the machines present in the network. Here, when one machine sends any data packet all the machine in the network receives that data. The data packet contains the address of the intended recipient. Once all the machines receive the packet, they check out the address field of the packet. If the packet is for the concerned machine, it processes the packet else it discards the packet. We also refer to broadcasting as multicasting.
The second dimension we talked about for classifying networks into different types is scale. Distance is an important factor that can be used as a classification metric. As different technologies are used for different kinds of scales. Let us see how we classify networks on the basis of scale:
PAN (Personal Area Network)
The personal area network allows devices to communicate over the range of an individual person. The range is almost over 10 meters. The best example of this is the connection of the computer with its peripherals.
Usually, we use cable for these connections but some companies have designed a short-range wireless network that we refer to as Bluetooth. Bluetooth technology is able to connect computer peripherals without wires. Bluetooth connects devices such as headsets to mobile phones, digital music players in your phone to your car, etc.
LAN (Local Area Network)
The local area network is a private network that is used to connect the computer systems present within and nearby building. Usually, LANs are used to connect personal computers to electronic devices such as printers.
These days wireless LANs is popular for connecting computers at home, offices, cafeterias, malls, etc. This helps us in getting rid of too much of cables that would have been used to connect devices. Well in wireless LAN each computer has a radio modem and antenna installed in it that helps it to connect with the other computers in the network.
Example of a Wireless LAN is – WiFi which has a transmission speed of 11 to 100 Mbps.
Now a wired LAN uses a different transmission technology that involves coaxial cable, twisted-wire cable or even optical fiber.
Example of a Wired LAN is – Ethernet which has a transmission speed of 100 Mbps to 1 Gbps. The newer LANs are even transmitted data at the speed of 10 Gbps.
If we consider the performance, wired LAN always performs better than wireless LAN.
MAN (Metropolitan Area Network)
The metropolitan area networks connect the computers within a metropolitan area. This metropolitan area could either be a single large city, or a group of cities and towns. MAN is larger than LAN but is smaller than WAN.
WAN (Wide Area Network)
Network topology defines the structure in which the computers are connected in the network. Let’s discuss each of these topologies.
- Bus – In a bus topology, all computers are connected to a common medium
- Ring – In the ring topology, each computer in the network is connected to both (left and right) of its neighbor in such a way that if a node has to reach some other node in a network then it has to traverse nodes left-or rightwards.
- Tree – In the tree topology, all the nodes in the network are arranged hierarchically.
- Star – In star topology, all the nodes are connected to a centralized node.
- Mesh – In the mesh topology, each node in the network is connected to arbitrary numbers of nodes in the network.
- Hybrid – It is a combination of various topologies we studied above.
Uses of Computer Network
We need a computer network to connect all the computers in the company. This enables all the computers to share all the programs, tools, and data no matter what is the location of the resource or the user.
You might have heard about the VPNs i.e., Virtual Private Networks that is used to connect individual networks at different sites into extended one.
The computer network connects home users to other remote users. It allows home users to access information at some remote locations, communicates with other home users, for online shopping, visits social media platforms, etc.
Now a day mobile computers or portable computers such as laptops or handheld computers such as tab etc. are the fastest growing segments of the computer industry. Like desktop computers, we also use mobile computers to send emails, visit social media platforms, download videos, and audio, play games, or surf the world wide web.
The user wants to do all the above activities from land, air, and even seas. And for this, the mobile computer needs to be connected to the network.