"Are you new to Linux or just a little rusty?" asks Dave McKay in
"Here are all the commands you'll need to know. Think of this as an essential reference for the Linux terminal. This applies to the macOS command line, too...
Linux includes a large number of commands, but we've chosen 37 of the most important ones to present here. Learn these commands, and you'll be much more at home at the Linux command prompt.
The below list is presented in alphabetical order. A command's position in the list is not representative of its usefulness or simplicity. For the final word on a command's usage, refer to its man pages..."