what is background application for linux?
 

can anyone told me about the background application, i need find out about 10, but is hard to find it on the net...thank you.

Anything can be a potential 'background' application. Use the 'ps' command to se information about running processes. For example:
# ps -eaf

There is further information in '/proc/'
Each process will have its own directory, for example '10', look in that directory for more information on the process.

Do you mean an application that runs in the background?

Or maybe an applications with the name of "background"?

Or maybe an application to make backgrounds?

And you need 10 of them?

Ask your professor?