Finder sidebar
Finder windows have a sidebar that provides quick access to items you use frequently.
If you don’t see the sidebar, press Control-Command-S.
The sidebar is divided into four sections: Favorites, iCloud, Locations, and Tags. If you don’t see any items in a section, they may be hidden—click at the right of the section to reveal any hidden items.
To customize the Finder sidebar, click in the Dock, choose Finder > Settings, click Sidebar, then select the items you want to see in each section.