Feedback List of default buttons needed

I'm working on getting a character to move, jump, etc., but I'm not getting very far. I know that movement is supposed to be handled by Input.GetAxis and other actions by Input.GetButton; so far, so good. But where's the list of buttons? What format are calls to GetButton supposed to be in? As far as I can tell, the scripting reference doesn't say.

 

https://docs.unity3d.com/ScriptReference/Input.GetButton.html