If you deactivate a team member, they will no longer be able to sign in, though their account will remain in the Users section and can be reactivated at any time. Their History and Analytics will still be viewable and the account holder can also reset their password or delete the account.
If a team member is deleted, their account will move to the Previous Users tab, and only the Analytics or their History will be available - further analytics will be removed from the User Analytics tab.
Note: a team member can be re-invited under the same email address again, however, no analytics or history will be show when the new account is activated, (i.e.: the previous history and analytics affiliated with said email address will not reflect).