Being able to edit your $PATH is an important skill for any beginning Linux user.
When you type a command into the command prompt in Linux, or in other Linux-like operating systems, all you’re doing is telling it to run a program. Even simple commands, like ls, cd, mkdir, rm, and others are just small programs that usually live inside a directory on your computer called /usr/bin. There are other places on your system that commonly hold executable programs as well; some common ones include /usr/local/bin, /usr/local/sbin, and /usr/sbin. Which programs live where, and why, is beyond the scope of this article, but know that an executable program can live practically anywhere on your computer: it doesn’t have to be limited to one of these directories.
Read more at OpenSource.com