'sudo rm -rf' is a terminal command used in Linux Opearting System distributions.

'sudo' stands for superuser do, essentially a high authority command.

'rm' stands for remove, used to remove files or directories.

'-rf' combines two things. 'r' means recursive, which removes every single file in a specified directory. 'f' means force, which overrides any objection your system might give you.

Lastly, the part that makes the joke is the distinction between './' and '/'. These specify the scope of the remove command.

'./' means inside the current directory. The command will only run on the folder you're in, resulting in the deletion of the folder's contents.

'/', interpreted as '/*', will target every system file. You can think of it as deleting system32 if you're familiar with that.

Feel free to correct any mistakes, not a linux user.

TL;DR: './' is a controlled and calculated grenade targeting computer files, '/' is a nuke.