The which command is the simplest of the three. When you use it to ask about a Linux command, it will run down your search path looking for executable files by the name you specify. These can be ...
Did you know you can check the maximum speed of a USB port with one command?
You don't need to live in the Linux terminal.
Complete tload command guide for Linux. Monitor CPU load average with live ASCII graphs. Installation, usage examples, and comparison with top/uptime.