tell me about client server computing it will be very usefull for me.......

When you say client/serve computing, it can mean several different things. Are you referring to a Database -> Client or are you talking about System Administration.

On Database-> Client, the user interacts with a Database. The database resides as the Backend tables that has the data whereas the Front End is what the user sees and interacts with.

On System Administratioon -> This could mean File/Print Services including File and Folder maintenance or Print Server Maintenance.

Usually, CSA entails people (clients) interfacing with Information (Server and Database) to obtain a desired result.