In the case you want to delete, deactivate or archive an account from your group, it's important to note that all user activity is stored in the database for you to report on. In the instance you want to purge all traces of a user, please do contact our email@example.com
Common instances in which user accounts have "traces" of data, e.g., the status or role "Registered" to an event or "Bought" a ticket. You'll notice when reviewing the User Memberships Manage page, there is a role called "Registrant" or "Ticket Buyer". Instances like this where the user has done any of the above will provide "remnant" data on how they interacted with your group. This will be helpful for you to oversee and determine the long-tail interaction of your users and advocates.
There are instances where you have users who move away, graduated or no longer affiliated but you still as an administrator want to retain their information, you can do so by "archiving".