"A thread is a message vehicle to make a statement, ask a question, give directions, etc. A new thread post is the start of that vehicle. Each answer or comment posted as a reply to that thread, is attached (sewn or threaded) to the original message. This is done to keep replies associated with the appropriate post. One other thing about threads, is they can be associated with a page, giving a more organized way to keep threads together instead of helter skelter. "