What is a deactivated user?

When working on the members page of a Standard or Premium Workspace, you may see a user who shows as "deactivated": 

These users have had their access to the Workspace, Workspace-visible boards, and boards in the Workspace of which they were a member removed. They can still access non-Workspace content that their account had access to (such as content on other Workspaces, or their own private boards). Deactivated users do not consume a seat license on the Standard or Premium Workspace.

Deactivated users, unlike removed/deleted users, remain assigned to cards on boards where they were a member. Though they cannot access the cards, this is helpful for remaining Workspace members to transfer the work of a former colleague on to the person who is taking over that role. Removed users, on the other hand, disappear from boards and cards completely (so there's no visible indicator of what work needs to be taken over).

Deactivating a user

To deactivate a Workspace member, open the Workspace Members page and near the user's name choose 'Remove', then choose the option 'Deactivate'. 

Reactivating a user

Reactivated users will regain access to Workspace-visible boards and any boards in the Workspace of which they're a member. Workspace admins can reactivate the user by clicking on the reactivation link near the user's name on the Members tab.