Mkdir: Create multiple directories with one command

mkdir regular syntax.

mkdir [options]

mkdir -p syntax.

-p = Parent directory

mkdir -p [directories]

Syntax to create a chain of child directories.

mkdir -p /first/second/third

Syntax to create more than one directory at a specific level.

mkdir -p first/{second, also_second}

Just a fun tidbit that makes life a bit more efficient on Linux!