Adding spaces to your dock lets you group similar apps. It is super easy to do. Let me show you how.
Open Spotlight by pressing command + space. This opens up a search bar. Here you type in "terminal" and hit enter. This will open up a small window where you can type in commands. Now enter the following command.
defaults write com.apple.dock persistent-apps -array-add '{"tile-type"="spacer-tile";}'; killall Dock
This will create an empty slot in your dock which can be moved just like any other icon in your dock by drag and drop. It can also easily be removed by just drag and drop it outside of the dock.
