The tips window is a new form of getting help in Scratch. It is built directly into the editor, a bit like the help dialog of 1.x. It is always visible, even when zoomed in with the browser or when viewing a project in full screen.
The Scratch Wiki is a free, collaboratively-written wiki that provides information about the Scratch programming language and its website, history, and phenomena surrounding it. The wiki is supported by the Scratch Team, but is primarily written by Scratchers. The Scratch Wiki is a popular source of information for scripts and tutorials, and it continues to grow as Scratchers use it as their primary source of information.