All they do is guarantee that a type has methods A,B,C available.
What might be slightly confusing are trait bounds on generics. They are kind of like traits themselves but not exactly. They implicitly say "this generic parameter must make methods A, B, C available via Trait X".
Very few things are truly intuitive, they just happen to be similar to other things you've done and so you've got a step up on understanding them. Really good software engineers tend to be constantly playing with things outside their usual domain and so have broader range of concepts they can reach for when the time comes.
all i wanted was to add a new method i could call in the same way as all the methods on Iterator (map, filter, etc.). and was suddenly confronted with `impl Trait2 for T where T: Trait1`. which makes perfect sense now. but at the time was unparseable.