SERVERS BASSIC INTRIDUCTION ,TYPES AND THEIR FUNCTIONALITIES

1. | Servers – Web Servers, DB Servers |
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Server (offering services to the connected devices)
• It is a computer or system which provides resources, data, services or
programs to clients (other computers) over a network (providing
information to client computers which are connected to it through
internet).
• It is a physical computer that provide services to all the client
computers connected to it, allowing them (client computers) to access
available information or resources
• It is a one that is responsible to provide response to each client’s
request simultaneously
• A server can process a single request or multiple requests at a time
• In short, it is a software or hardware which provides services to other
hardware or software entity
• A client can connect to a server through a local area network (LAN) or
a wide area network (WAN) like internet
• Server is called as host on a network
Client
• The devices that are connecting to the server is called as clients
Figure 1 - Client Server Architecture
SERVERS

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SCREENSHOT
ROLE
• The main role of the server is used to share data, resources and
distribute work.
USAGE OF SERVERS
• When users connect to the server, they can access files, programs and
other information from the server.
IMPORTANCE OF SERVERS
• A server can be set up by user for the following usages
▪ To control access to a network
▪ Send / receive e-mail
▪ Manage print jobs
▪ Host a web site, etc,..

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TYPES OF SERVERS
• Web server
• Database server
• Application server
• Data Centric Server
• Cloud Servers
• Mail server
• Print server
• E-mail server
• File server
WEB SERVER (WEB SITES)
• It refers to hardware (device) or software or both of them working
together
• It is a special type of the application server which is used to host the
web site (web pages) through the internet
• Web server respond to requests from browsers running on the client
computers for web pages or other web based services
• Each web site has one or more number of web servers. Also each
server can host multiple web sites
• It stores all the files for a web site.
• Web server simply use GET and POST requests from the clients
• Through the GET request, client will retrieve the information from the
server and does not have any information to submit to the server.
• Through the POST request, client will send / share the information to
server and expects a response back.
• Example. Submission of form requests on a web server and clicking
the submit button is a POST request from the client to the server
• When you a visit a website you are actually accessing a web server
which holds webpages for that web site

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Main Task of Web Servers
• It’s main task of the web server is to display the static web content like
HTML pages, files, images, video, etc in response to HTTP requests
from a web browser (client)
SCREEN SHOT 1
SCREEN SHOT 2
Web Server
(Connecting to
www.annauniv.edu)

5. | Servers – Web Servers, DB Servers |
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• One student access www.annauniv.edu by connecting to the web
server holding the www.annauniv.edu site which contains course
materials
• Meanwhile other students can be accessed the same material from
their computer, tablet, smartphone, etc, through the internet.
EXAMPLE OF WEB SERVERS
• Apache Web Servers (Apache HTTP Server)
• Microsoft Internet Information Services (IIS) servers
• Nginx servers
FEATURES OF WEB SERVER
• Web server has some important features. They are
▪ It handles HTTP Protocol (static contents)
▪ No need for server-side Programming.
▪ It supports web applications (JSP, Servlets, PHP, HTML, etc.)
▪ Does not support Database Connection Pooling.
▪ Does not provide EJB support.
DATABASE SERVER
• The amount of data used by companies, users, and other services is
stored in databases
• It provides access to a database
• It is a one type of the server which manage the database of the
organization
• It is a type of server which uses a database application that provides
database services to other computer programs or to computers
• It is delegated to database storage, queries and retrieval tasks, etc,…
• The backend sometimes is called as database server which performs
tasks like data storage, data manipulation, archiving, data analytics
and other tasks
• Programmers / users can create databases and access databases on
the servers using scripting languages like python, PHP, etc
EXAMPLE OF DB SERVERS

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• Oracle
• DB2
• SQL Server
• Informix
• MySQL Server, etc, …
APPLICATION SERVER
• It is a server type which is used to host (store) the applications
• It provides both ways to create a web application and a server
environment to run them
• It is sometimes mixed with a web server. While a web server handles
mainly HTTP protocols, the application server deals with several
different protocols like including but not limited to HTTP
Main Task of Application Servers
• The main task of the application server is to enable interaction
between clients (end user) and server side code which is called
business logic via server side languages like PHP, JSP, Python, .NET,
etc, …
• Business logic – to deliver the dynamic web content such as decision
support, database results, real time analytics, etc,…
• Like web server, it also delivers the web content
FEATURES OF APPLICATION SERVER
• Application server has some important features. They are
▪ It provides dynamic business logic
▪ It helps you to manage backend services like calculations,
processing, calculations, etc,…
▪ It helps users to deploy applications, security, etc,…

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EXAMPLES
• Apache Tomcat
• Glassfish
• JBoss, etc,. …
DIFFERENCE BETWEEN WEB SERVER AND APPLICATION SERVER
S.N WEB SERVER APPLICATION SERVER
1. It is a computer application or
computer which runs the
application
It is a type of web server that
helps you to host the
applications
2. It is responsible for handling HTTP
requests from clients and providing
HTTP response back to clients
It exposes business logic
(application code) to clients, that
generates the dynamic content
3. It consumes less resources like
CPU, memory, etc
It utilizes more resources
4. It supports only HTTP protocol It supports HTTP protocol as
well as RPC/RMI protocols
5. It delivers static web content It delivers dynamic content