Introduction to Servlets

           We use Servlets to develop the web based applications. To run a web based application we need a server and a client. In a web based application Client sends the Request to the server, the server receives that request, processes it and send the Response to the client. So, in a web based application both server and client are equally important. The following figure shows you the client and server architecture. 

Fig1: Client Server Architecture

If the client and server want to communicate with each other they must use same protocol. There are so many protocols available to us. Some of them are: 

• TCP/IP
• SMTP
• UDP
• FTP 
• HTTP etc...,

Among all these protocols, HTTP is the only protocol which is used in the web applications.

Disadvantages of Standalone Application: 

Standalone application is the one that can run offline. The following are the disadvantages of the Standalone applications:

• As the Standalone application runs on the client computer, we need to install it in all the computers. 
• We will have a lot of maintenance related problems, i.e., whenever we want to change the project we need to change it  in every client computer.
• A standalone application consumes the resources of the client computer.
• Only some persons know how to install these application and configure them.