Understanding the Console
A word on programs
A common misconception is that things like mkdir, rm or adduser are different from things you install in your system (e.g. postgresql, or mongod). They are not. All of them are programs. Some already come installed, and others you have to install yourself. You can find out where a program executable lives using the which program: $ which mkdir /bin/cd $ which which /usr/bin/which However, there are some built-in commands in the Bourne Again SHell (BASH). They are not very many:
