If you open the Publishing Options entry at the bottom of an editing page you will see
Published - this article is available for other users to see. (You might want to unset this if you want to keep a draft of your article for later work.)
Promoted to front page - your article teaser will appear as one of the items on the front page.
Sticky at top of lists - useful for introductory forum articles which everyone should read. Your item won't disappear as newer items are created. Only use this for VERY IMPORTANT articles.
Create new revision - Useful if you are working with other people and need to manage the copies of a document.