Sidebar is structural and persistent — it's part of the page's identity. Sheet is user-triggered, contextual, and closes when the task is done. Drawer is the same idea, but session-scoped and temporary rather than tied to one item.
Page content
Sidebar never closes — it's always part of the layout.
Closes when you're done with that specific row.
Not tied to a specific item — closes when the session's task is done.