Guest users are only available in paid workspaces and can either be single- or multi-channel guests.
There can only be one primary owner per workspace although the primary ownership can be transferred to another user.
Workspace admins can are primarily intended for member management but also have access to administrative functions and tasks.
To do so, need to first go for the workspace name in the top-right corner.
choose the Menu burger menu in the top-left corner, then choose About this workspace.
Switch to the Admins & owners tab to view the list of workspace owners and administrators.