ls directories | List Unix directories only

In order to ls directories or list directories (excluding regular files) use the -d flag with the pattern */.  The -d flag stands for 'directories' and the pattern */ for 'all directories in current folder'.

Putting it together use:

ls -d */

• */ -> all directories in current folder
• -d -> list the directories themselves, not their contents
• Result -> a simple list of directories only