A computer application (a web browser) is a client program that runs on a local computer and connects to a server. Operations may be performed client-side because they require the access to information or functionality is available on the client but not on the server. The user performs the operations without sending data over the network; it is not so time consuming and risky than performed on the server.
Modern web browsers can request and receive data using HTTP (HyperText Transfer Protocol) and FTP (File Transfer Protocol) protocols. Users can choose a number of client programs or write their own server, client, and communication protocol, which can be used only together.
Server-side operations are performed by the server in relationship with client in a computer networking. Server-side technologies perform operations of processing and storage of data from a client to a server, which can be viewed by a group of clients.
A server is a software program (a web server), for a distant server, that local computers can reach for different purposes. In this case local computer demands access to information or functionality on the server to perform operations.
Client-side programming on the client computer has some advantages such as fewer security risks. Still server-side programming is more secure and is preferred by most programmers. Server-side programming offer more possibilities for languages than client-side.
Ajax is a good example of technology that uses both client-side scripting and server-side scripting. Ajax acts like a client-side script that calls a server-side script. This is a new and worth trying technology that will save you time and efforts.