Which terminal command — probably the most-typed two letters in computing history — answers 'what's in this folder?'

The command ls lists the contents of the current folder, showing you every file and subfolder inside it, and it is likely one of the most frequently typed commands in the entire history of computing given how constantly people need to check what's in a directory. Adding options extends its behavior, such as -a to reveal hidden files or -l to show detailed information like size and permissions.

'go' and 'hi' are simply invented words with no function in real terminal command sets; they exist here only to make the correct, real command stand out by contrast.

Learning that commands can be extended with dash-prefixed options, like ls -a or ls -l, is one of the very first pieces of terminal grammar beginners pick up, and it applies across almost every other command too.