Thread

A Daemon Thread will run until it completes or until all User Threads
have completed.  Daemon threads make excellent "behind the scenes" 
processes for things that must happen in the background but can be 
terminated when the application ends- garbage  collection is a great 
example of a process that could be handled with a daemon thread.
Once all User Threads complete, any Daemon Threads that are still 
running are  automatically halted and the application terminates.

Hope this will help you !!