What is a command window.And index generation?

Today when i went to shut down my pc i got a message saying something about a commandwindow.Asking me do i want to end it now,before the shut down.

What is a command window?

And if i ever use limewire....sometimes if i decide to shut down my pc,i get a message saying index generation do you want to end now.

I just would like to know what these things are.

Thanks

A command window is what you get when you click on Start, Run and type in cmd and press Enter. That little black screen.

Also known as the Command Prompt.

As far as P2P applications go, index generation usually means that the program hashes the files you share, creating an index or indexes that facilitate other users' searches.