What the bell shows. The bell holds this workspace's notifications: syncs you started, team activity, account notices. Each row carries a mark: a person's initials when someone acted, a category icon otherwise. Switching workspaces switches the bell: each workspace keeps its own list and its own unread count. A few notices about your account rather than any workspace appear wherever you are.
Reading them. Opening the bell marks the current workspace's notifications read. Another workspace's unread items stay unread until you visit it.
Preferences. Settings → Notifications holds your switches for the workspace you're in: whether action-required notices also reach you by email, and whether you hear when a teammate acts on a recommendation or a finding. Other notices always arrive in the bell. A workspace you haven't adjusted follows the preferences you set before per-workspace control existed, then the defaults. Changing a preference in one workspace never changes it in another.
Emails. Two kinds of action-required notice can also arrive by email: a source that needs reconnecting, and notices about your AI allowance. The Action-required emails switch turns them off for this workspace. Invitations and replies to your support requests always arrive.