There are the Avengers, the New Avengers, Avengers 1959, how are they related? Also is the New Avengers basically uniting the entire Marvel universe?

• The Avengers are the Avengers. That's it.
• The New Avengers started out as the replacement for the Avengers after the events of Disassembled. Now, they don't really serve a purpose at all, and can/should be ignored.
• Avengers 1959 is a group that Nick Fury started back in (take a guess) 1959, and don't matter in the slightest currently.
• The Young Avengers are a team of teen superheroes that take inspiration from the Avengers, and really have no associations with the Avengers other than that.
• The Secret Avengers is basically a black-ops team that, again, really have no relation to the main Avengers team.
• The Dark Avengers are a team of villains that Norman Osborn dolled up to make the Avengers look bad.

You know if you read the first few senses on each of the wiki's here I'd doubt you'd have these questions.