Whoami
With SSH, su, and other programs, you can sometimes lose track of where you are and what user you are logged in as. You can use the command whoami to tell you what your current session username is.
[bradr@ssh8-2 ~]$ whoami bradr
Similarly, you can use the command who to tell you who all is logged in to the same server as you and also where they are connecting from.
[bradr@ssh8-2 ~]$ who root tty1 2023-01-04 15:00 bradr pts/0 2023-01-05 09:23 (147.126.10.105)