COMPUTER NETWORK
A computer network is a collection of computers and other external devices (such as printers and modems) connected utilizing communication links. The fundamental objective of a computer network is to facilitate the sharing of data and hardware resources among a wide range of users. The computers in a system can link through cables, telephone lines, radio waves. The complexity of a computer network may vary from just two computers connected to a network combining millions of computers totally across the globe.
NOTE; - This image is taken from this site I do not belong from this image.
NOTE; - This image is taken from this site I do not belong from this image.
When you connect your computer to a network via a cable means you become a network user and your computer becomes a workstation for sometimes called node) on the net. Your computer can access all its local resources such as local hard drives or printer. It can use the network resources, including printer, disk storage space. For example, you can print a document on the printer attached to some other
computer on the network.
Advantages of a Computer Network
A networked environment of computers has several advantages. Some of these give below: -
Speed- You can share and transfer files within a computer network very rapidly. It sure
times while maintaining the integrity of data.
Communication- A computer network facilitates communication via email
videoconferencing and instant messaging.
Information sharing- In a networked environment, the information can keep.
A single computer is known as the server. All the other computers in the network can access
the information stored on the server.
Resource sharing- The primary aim of networking is to share resources regardless of the
the physical location for better communication Resource sharing involves the sharing of
both the hardware and software resources among the multiple users connected to the
network.
Preservation of Information- It is easy to take a backup of data in a networked environment
rather than on several stand-alone computers.
Cost-effectiveness- Due to the interconnection of computers, it is easier to access and
transfer a large amount of data from a far distance in a cost-effective manner and a
short period.
Reliability- The backup facility in networking makes it a reliable model for communication.
And sharing files. In case one computer in a network fails, the data can access from other computers.
Disadvantages of a Computer Network
Some of the disadvantages of a computer network given below:-
Security- One of the significant drawbacks of computer networks is the security If
the proper network security check not performed, there is a possibility of the theft of
confidential and private data.
Dependency on the server- If the server breaks down the working of all the computers on the network disrupted, and the entire system becomes useless.
The rapid spread of computer virus- If any computer in the network gets affected by a computer virus, other computers can also be affected. There is a possibility that that virus can corrupt essential data.
Expensive- The setup cost of a computer network can be high, depending on the number
of computers to be connected.
Degraded performance- If the traffic of data increases on the network, the performance of
the system degrades if it not appropriately designed.
TYPES OF NETWORKS
Computer networks can be categorized based on their size, the distance they cover, and the
Links used for their interconnection. According to the physical distance, a computer network.
covers, it can categorize into four types, namely (MAN), (LAN), (WAN), (PAN), Personal Area Network, Local Area Network, Metropolitan Area Network, and Wide Area Network.
Personal Area Network (PAN)
A PAN is the least reasonable network signified for one person. It is used to interconnect individual devices such as a computer, laptop, mobile phone, tablet, or any other hand-held the method of an individual. The ways in a PAN are Printer linked together either using cables or wirelessly. In wired PAN, the devices communicate PDA through a USB cable. While in a wireless PAN, Bluetooth and infrared technologies used for Laptop communication. This network can cover an area Desktop of only a few meters (less than 10 meters).
Local Area Network (LAN)
A LAN is a network that reaches a comparatively small region such as an apartment. Generally, it comprises interconnected personal computers, which is capable of obtaining and giving data and devices such as (printers and scanners), anywhere on the LAN.
A LAN does not pass an area of two to three square kilometres. It may assist as few as two or three users up to hundreds of users. This networks are owned, controlled, and managed by a single person or an organization.
Metropolitan Area Network (MAN)
A MAN is a network that covers an area of a city. It is formed by connecting multiple LANS One or more organizations may own it. An example of a MAN is the cable TV networks that spread over a city. It is more efficient and provides a high-speed connection using fibre optic cables.
Wide Area Network (WAN)
AWAN is a network that spans a large geographical area such as several cities or even countries.
It connects different smaller networks, including LANs and MANs.
Computers in a WAN often connected through public networks such as telephone systems.
Sometimes, satellites also are wont to connect computers in a very WAN.
The Internet is associate degree example of a wide used WAN.
NETWORK ARCHITECTURE
Network architecture refers to the layout of a computer network that specifies how a computer network is configured to facilitate information exchange and resource sharing, The two major.
types of network architectures are a client-server and peer-to-peer network.
Client-Server Network
In a client-server network, many workstations (called clients) connected to a centralized
Bost computer is known as a server. To accomplish any task, the client requests a service like data retrieval from the server, and the server responds by providing the service. Also, assist clients, the server controls access to hardware, software, and another network resource.
Peer-to-Peer Network
A peer-to-peer network does not rely on a central server for communication. Instead, the
Computers having equal capacity and capability (called peers) are connected to Use the resources on the network. Each computer on a peer-to-peer network can act both as a server and a client.
INTERNET, INTRANET, AND EXTRANET
The Internet is the largest network that connects countless computers worldwide to share
iInformationand service. People all over the world and use the Internet for various purposes
like web send mails watch videos play online games and download data
Moreover, an intranet is a private computer network owned by a company or an organization and
access to its employee ft closely related to the Internet but has a protecting system
To prevent authorized access from external computer networks. Thus, it has a limited number of Bluetooth. It uses the Internet protocols, network connectivity, and telecommunication system to share part of the organization's information or operations with its employees.
An extranet is a computer network that allows outside users to have limited access to the part of the organization's data. These users include vendors, suppliers, or customers that may need to access the organization's data for some business purposes or customer services.
PROTOCOLS
The communication between computers is possible by using a protocol that offers a standard format. Another method for communication protocol is a formal set of rules and how computers exchange information over the network. There are a large number of contracts that can be used in a system, depending on the need they fulfil. Two of these discussed here: -
TCP/IP(Transmission Control Protocol/Internet Protocol) It the suite of communication
Protocols which used as a standard for transmitting data over networks. TCP/IP consists
of two contracts, namely, TCP and IP TCP is responsible for dividing the message or
file into small packets at the source computer that transmitted over the network Then
at the destination computer, it resembles the packages into the original word or file
On the other hand, the IP handles the address part of each packet so that it reaches the
right destination Any computer or a device which connected to the Internet must be
supported by TCP/IP
HTTP HyperText Transfer Protocol: It is the Internet protocol responsible for transferring and viewing web pages. It provides a way for web clients and web servers to communicate
with each other by sending and receiving messages.
DATA TRANSMISSION MEDIA:
Data transmission media refers to the medium used for transmitting data between the Connected devices in a network Transmission media can be broadly classified into guided and unguided media. Guided media: - (also called wired press) provides a physical path between the communicating devices in a network mainly used for small LAN. Different Voes of guided media include twisted pair cable, coaxial cable and fibre optic cable.
Unguided media: - An unguided press (also called wireless news) is a type of transmission
media that sends or receive the data through space does not involve any cable between two communicating devices.
