The network used during and after corona

Contents
NETWORK................................................................................................................... 1
uses of network....................................................................................................... 2
tasks of a network................................................................................................... 2
advantages of networks.......................................................................................... 3
Disadvantages of networks..................................................................................... 3
Network Characteristics.......................................................................................... 3
Network Models Peer to Peer and Client and Server...............................................4
PEER TO PEER NETWORKS................................................................................... 4
Criteria for selecting peer to peer........................................................................5
CLIENT SERVER NETWORK...................................................................................... 6
Types of network..................................................................................................... 6
LAN....................................................................................................................... 7
MAN...................................................................................................................... 7
WAN..................................................................................................................... 8
Network Topologies................................................................................................. 8
The Role of Computer Networks in Modern World......................................................9
How network used in old ERA................................................................................ 10
The network used during and after corona...........................................................10

NETWORK
 A network is a group of two or more computers or other electronic devices
that are interconnected for the purpose of exchanging data and sharing
resources.
 The connection of at least two computer systems, either by a cable or a
wireless connection.
 The simplest network is a combination of two computers connected by a
cable. This type of network is called a peer-to-peer network. There is no
hierarchy in this network; both participants have equal privileges.
 Each computer has access to the data of the other device and can share
resources such as disk space, applications or peripheral devices.
 Today’s networks tend to be a bit more complex and don’t just consist of two
computers. Systems with more than ten participants usually use client-server
networks.
 In these networks, a central computer (server) provides resources to the
other participants in the network.
uses of network
 file sharing- which enables users to share data files through a network;
 application sharing- which enables users to share applications through a
network;
 hardware sharing- which enables users in a network to share hardware
devices, such as printers and hard drives;
 client-server model - which enables data to be stored on servers, where
end-user devices -- or clients -- can access that data;
 voice over IP (VoIP)- which enables users to send voice data through
internet protocols;
 communication- which can include video, text and voice;
 e-commerce- which enables users to sell and buy products over the
internet; and
 gaming- which enables multiple users to play together from various
locations

tasks of a network
The main task of a network is to provide participants with a
single platform for exchanging data and sharing resources. This task is so important that
many aspects of everyday life and the modern world would be unimaginable
without networks.
Here’s a real-life example: In a typical office, every workstation has its own
computer. Without a network of computers, it would be very difficult for a team to
work on a project since there would be no common place to share or store digital
documents and information, and team members would not be able to share certain
applications.
In addition, many offices only have one printer or a few printers that are shared by
everyone. Without a network, the IT department would have to connect every single
computer to the printer, which is difficult to implement from a technical standpoint.
A network elegantly solves this problem because all computers are connected to
the printer via one central node.
advantages of networks
 Peripherals such as printers can be shared amongst many different users
 Terminals are cheaper than standalone PCs
 Software can be shared amongst different users.
 Communication across the network is cheap and fast.
Disadvantages of networks
 Cabling can be expensive to install and replace.
 A fault with the server will prevent the whole network from working.
 Security mesures are needed to restrict access to the network.
 WANs are vulnerable to hackers and viruses.

Network Characteristics
 Networks are broadly classified into two types: local area networks (LANs)
and wide area networks (WANs).
 The WANs are also referred to as long-haul networks.
 The key characteristics that are often used to differentiate between these two
types of networks are as follows:
o Geographic Distribution:
The main difference between the two types of networks is the way in
which they are geographically distributed. A LAN is restricted to a
limited geographic coverage of a few kilometers, but a WAN spans
greater distances and may extend over several thousand kilometers.
Therefore LANs typically provide communication facilities within a
building or a campus, whereas WANs may nationwide or even
worldwide.
o Data rate:
Data transmission rates are usually much higher in LANs than in
WANP- transmission rates in LANs usually range from 0.2 megabit per
second to 1 gigabit per second. On the other hand, transmission rates
in WANs usually range from 1200 bits per second to slightly over 1
Mbps.
o Error rate:
Local area networks generally experience fewer data transmission
errors than WANs do. Typically bit error rates are in the range of 10 to
the power of -8 to 10 to the power of -10 with LANs as opposed to 10
to the power of -5 to 10 to the power of -7 with WANP-
o Communication link:
The most common communication links used in LANs are twisted pair,
coaxial cable and fiber optics. On the other hand since the sites in a
WAN are physically distributed over a large geographic area, the
communication links used are by default relatively slow and unreliable.
The communication links used in WANs are telephone lines, microwave
links and satellite channels.
o Ownership:
A LAN is owned by a single organization because of its limited
geographic coverage. A WAN is usuall formed by interconnecting
multiple LANs each of which may belong to a different organization.
Therefore administrative and maintenance complexities and costs of
LANs are usually much lower than for WANs.
o Communication cost:
The overall communication costs of a LAN is usually much lower than
that of a WAN. The main reasons for this are lower error rates, simple