Yeah, in very general terms, it's plants and fungi (and minerals, like salt) that you eat when on a vegan diet. So, for the most part, you're abstaining from meat/fish, dairy, eggs, honey and gelatin.

Of course, there's lots of room for interpretation, because you can follow a vegan diet either just for health reasons or for ethical reason, and there's different philosophical viewpoints on those ethics as well.
For example, some folks subscribe to vegan ethics but still keep backyard chickens and eat their eggs, because the end-goal is avoiding animal harm (where reasonably possible) and they feel like they can do that, when they look after the chickens themselves...