A computer network connects multiple devices together to allow communication and sharing of data and media. There are different types of networks including local area networks (LANs) that connect devices within a building, and wide area networks (WANs) that connect multiple LANs across large geographical areas using routers. Virtual private networks (VPNs) allow remote access to a network through the internet. Computer networks rely on network devices like routers, switches and hubs to facilitate communication between devices. Servers and clients are key components, with servers processing requests and delivering data to clients like personal computers. Common servers include web, email, file transfer protocol and identity servers.

1. Computer Networks

2. Computer Networks
A computer network is an interconnection of multiple
devices, also known as hosts, that are connected using
multiple paths for the purpose of sending/receiving data or
media. Computer networks can also include multiple
devices/mediums which help in the communication between
two different devices; these are known as Network devices
and include things such as routers, switches, hubs, and
bridges.

3. Types of Computer Networks

4. LAN
LAN is the acronym for Local Access Network. A LAN
network is a short-distance network. It connects computers
that are close together, usually within a room or a building.
Very rarely, a LAN network will span a couple of buildings.
An example of a LAN network is the network in a school or
an office building. A LAN network doesn’t need a router to
operate.

5. WAN
WAN stands for Wide Area Network. WANs cover a
huge geographical area. A WAN is a collection of LAN
networks. LANs connect to other LANs with the help of a
router. The router has a LAN address and a WAN address,
which lets it send data to the desired location. The biggest
WAN in the world is, of course, the Internet. WANs are
different from LANs in that they’re not owned by a single
person/organization. They also use different technology that
enables them to communicate over long distances, like
Frame Relay and ATM.

6. VPN
VPN stands for Virtual Private Networks. VPNs are
very important today. They let you connect to your network
from a remote location through the Internet. This saves you
time and money- you don’t need to set up a physical
connection with your network. The Internet acts as a
medium between you and your network. For example, you
can access your computer at work through your computer
at home.

7. Parts of a Computer Network

8. Server
A server is a computer designed to process requests
and deliver data to another computer over the internet or a
local network. A well-known type of server is a web server
where web pages can be accessed over the internet
through a client like a web browser. However, there are
several types of servers, including local ones like file
servers that store data within an intranet network.

9. A large, general-purpose network that supports a medium-
sized company likely deploys several types of servers,
including:

10. Web server
A web server shows pages and runs apps through
web browsers. The server your browser is connected to
now is a web server that delivers this page and the images
on it. The client program, in this case, is a browser like
Internet Explorer, Chrome, Firefox, Opera, or Safari. Web
servers are used for many tasks in addition to delivering
simple text and images, such as uploading and backing up
files online through a cloud storage service or online backup
service.

11. Email server
Email servers send and receive email messages. If
you have an email client on your computer, the software
connects to an IMAP or POP server to download your
messages to your computer, and an SMTP server to send
messages back through the email server.

12. FTP server
FTP servers move files through File
Transfer Protocol tools. FTP servers are
accessible remotely using FTP client programs,
which connect to the file share on the server,
either through the server's built-in FTP
capabilities or with a dedicated FTP server
program.

13. Identity Server
Identity servers support
logins and security roles for authorized users.

14. Client
A client is a computer that connects to and uses the
resources of a remote computer, or server. Many corporate
networks comprise a client computer for each employee,
each of which connects to the corporate server. The server
provides resources like files, information, Internet and
intranet access, and external processing power. In the case
of processing, any work done on the server is referred to as
"server-side" work. Any work done on the local client is
similarly called "client-side."