What is Library
Library stores all the stuff you've visited, downloaded, created, or saved on Arc. You can open Library from the bottom-left icon in your Sidebar, or by hitting Command-T and typing "Open Library".
Library has 5 sections:
Access Recent Files
Hovering over the Library icon allows you to open and drag recent files. You can edit which items appear on hover by right-clicking the Library icon and selecting / deselecting certain file types.