This document provides an overview of computer networks including their history, goals, components, types, and technologies. It discusses how the ARPANET was developed in the late 1960s to enable resource sharing between computers. The key components that enable computer networks are described such as network interface cards, servers, clients, routers, switches, and cables. Different types of computer networks are defined including personal area networks, local area networks, metropolitan area networks, and wide area networks.

1. ASSIGNMENT ON : Computers network
SUBMITTED TO
Name : Pranab Bandhu Nath
Senior Lecturer, Department of CSE
City University
About Assignment
COURSE TITTLE : Computer Networks
COURSE CODE : CSE-312
ASSIGNMENT NO : 01
DATE OF SUBMISSION : 10-5-2021
SUBMITTED BY
NAME : Tanbir Ahmed Rabbi
ID : 1834902594
GROUP : B
BATCH : 49th
, DEPARTME : CSE

2. COMPUTER NETWORK
A computer network is a set of computers connected together for the purpose of
sharing resources.
U.S. defense department, funded the development of the Advanced Research
Projects Agency Network (ARPANET) in the late 1960s.
Goals of Computer Network
1. Main goal of networking is "Resource sharing", and it is to make all programs,
data and equipment available to anyone on the network without the regard to the
physical location of the resource and the user.
2. A second goal is to provide high reliability by having alternative sources of
supply. For example, all files could be replicated on two or three machines, so if
one of them is unavailable, the other copies could be available.
3. Computer organization has helped organization in saving money. This is due to
the fact that the small computer has much better price to the performance ratio
comparison than the large computer like mainframe. Mainframe computer are
approximately ten times faster that the microcomputers, but they cost thousands
times more. As a result of this imbalance, organization has preferred to install
interconnected microcomputer connected to the mainframe computer.
4. Computer network have provided means to increase system performance as the
work load increases (load balancing). In the days of mainframe when the system
was full it was to replace with the other large mainframe computer, usually at and
expensive rate not convenience for user.
5. Computer network help people who live or work apart to report together. So,
when one user prepared some documentation, he can make the document online
enabling other to read and convey their opinions. Thus computer network is a
powerful communication medium.
6. Only authorized user can access resource in a computer network. Users are
authenticated by their user name and password. Hence it is not possible to access
the data without proper account. This increases security.

3. Component of Computer Network
1. NIC: A network interface card (NIC) is a hardware component without which a
computer cannot be connected over a network. It is a circuit board installed in a
computer that provides a dedicated network connection to the computer. It is also
called network interface controller, network adapter or LAN adapter.
Purpose
 NIC allows both wired and wireless communications.
 NIC allows communications between computers connected via local area
network (LAN) as well as communications over large-scale network through
Internet Protocol (IP).
 NIC is both a physical layer and a data link layer device, i.e. it provides the
necessary hardware circuitry so that the physical layer processes and some
data link layer processes can run on it.
2. Server: A server is a computer or system that provides resources, data, services,
or programs to other computers, known as clients, over a network. In theory,
whenever computers share resources with client machines they are considered
servers. There are many types of servers, including web servers, mail servers, and
virtual servers.
3. Client: A client is a computer hardware device or software that accesses a
service made available by a server. The server is often (but not always) located on
a separate physical computer.
4.Peers: In networking, a peer is a node that provides the same functionality as
another. For example, two desktop PCs in a network are peers.
5. Transmission: Data transmission is the process of sending digital or analog data
over a communication medium to one or more computing, network,
communication or electronic devices. It enables the transfer and communication of
devices in a point-to-point, point-to-multipoint and multipoint-to-multipoint
environment.
6. Medium: In data communication terminology, a transmission medium is a
physical path between the transmitter and the receiver i.e it is the channel through
which data is sent from one place to another.

4. 7. Router: A router is a networking device that forwards data packets
between computer networks. Routers perform the traffic directing functions on the
Internet. ... A router is connected to two or more data lines from different
IP networks.
8. Bridge: A network bridge is a computer networking device that creates a single,
aggregate network from multiple communication networks or network segments. ...
Routing allows multiple networks to communicate independently and yet remain
separate, whereas bridging connects two separate networks as if they were a
single network.
9. Hub: A network hub is a device that allows multiple computers to communicate
with each other over a network. It has several Ethernet ports that are used to
connect two or more network devices together.
10. Switches: A switch is a device in a computer network that connects other
devices together. Multiple data cables are plugged into a switch to enable
communication between different networked devices. ... Switches may also operate
at higher layers of the OSI model, including the network layer and above.
11. Gateway: A gateway is a piece of networking hardware or software used in
telecommunications for telecommunications networks that allows data to flow
from one discrete network to another.
12. Repeaters: A repeater is an electronic device that receives a signal and
retransmits it. Repeaters are used to extend transmissions so that the signal can
cover longer distances or be received on the other side of an obstruction.
13. TCP: Transmission Control Protocol (TCP) – a connection-oriented
communications protocol that facilitates the exchange of messages
between computing devices in a network.
14.IP: IP stands for "Internet Protocol," which is the set of rules governing the
format of data sent via the internet or local network.
15.OSI: The OSI (Open Systems Interconnection ) is a conceptual framework used
to describe the functions of a networking system. The OSI model
characterizes computing functions into a universal set of rules and requirements in
order to support interoperability between different products and software.

5. 16. Twisted-pair cable is a type of cabling that is used for telephone
communications and most modern Ethernet networks. A pair of wires forms a
circuit that can transmit data. The pairs are twisted to provide protection against
crosstalk, the noise generated by adjacent pairs.
17. Coaxial cable: Coaxial (or “coax”) cable is a common type of cable used for
transmitting data over long distances. It can carry either an analog or digital signal.
... However, they all transmit data via a thin copper line in the middle of the cable.
Computer Network Types
1. PAN(Personal Area Network): A personal area network is a network concerned
with the exchange of information in the vicinity of a person. Typically, these
systems are wireless and involve the transmission of data between devices such as
smartphones, personal computers, tablet computers, etc.
It is an interconnection of personal technology devices to communicate over a
short distance, which is less than 33 feet or 10 meters or within the range of an
individual person, typically using some form of wireless technologies.
2. LAN(Local Area Network): A local area network (LAN) is a collection of
devices connected together in one physical location, such as a building, office, or
home. A LAN can be small or large, ranging from a home network with one user
to an enterprise network with thousands of users and devices in an office or school.
3. MAN(Metropolitan Area Network): A metropolitan area network (MAN) is
a computer network that interconnects users with computer resources in a
geographic region of the size of a metropolitan area. The term MAN is applied to
the interconnection of local area networks (LANs) in a city into a single larger
network which may then also offer efficient connection to a wide area network.
The term is also used to describe the interconnection of several local area networks
in a metropolitan area through the use of point-to-point connections between them.
4. WAN(Wide Area Network): In its simplest form, a wide-area network (WAN) is
a collection of local-area networks (LANs) or other networks that communicate

6. with one another. A WAN is essentially a network of networks, with the Internet
the world's largest WAN.
The first known WAN was created by the U.S. Air Force in the late 1950s to
interconnect sites in the Semi-Automatic Ground Environment (SAGE) radar
defense system. An enormous network of dedicated phone lines, telephones, and
modems linked the sites together.