Difference ->calling method through Thread , BackGroundWorker and delegate(BeginInvok

[sum_gupt]

Hello Friends,
Can anybody describe the the difference among
1> When we call a method through System.Threading.Thread
2> When we call a method through BackgroundWorker
3> When we call a method through defining a delegate( i.e. through BeginInvoke)

Thanks in Advanced for your Help.

[sum_gupt]

Hello Yueliang,
Thanks for your reply but
I am not asking when to use
1> Thread,
2> BackgroundWorker
3> Delegate ( BeginInvoke)

My Query is what is the difference among three when you call any method.
All the three make calls to the function asynchronously

Please read the question carefully and then reply.