So what can evocations produce, exactly?

Please forgive me for posting this here, as opposed to the official evocation section of the forum, but I figure something like this must get asked constantly; whereas people here, knowing I am new, might be a little less annoyed.

How does actual evocation differ from the popular image of it in the media (Faust comes to mind)? Who or what appears, and what can be accomplished by making them appear?

Check out EA’s interviews on You Tube, there are quite a few of them. A lot of great info there. Get his books, or others books on the subject. Check everything on this forum, so much info here that you can answer your own question by reading older posts.