A user has a few general settings, including whether that user is enabled, their display name, and their email address. Whether or not the user is a Space Admin is also a general user setting. Note that this will give the user access to everything within the space and potentially override any roles you give the person.
Profile Attributes are attributes the user has the ability to change on their profile when logged in. Preconfigured, these include first and last name and phone number.
User Profile Attributes are user specific attributes that are not available to the user to modify. Preconfigured, these include Organization, Department, Site, and Manager.
Any defined teams and roles will be available to add the user to. A user can be added to any number of teams and roles.
Note that the delete for a user is at the bottom of this user screen. Note that this does not reassign any tasks that were assigned to this user or cancel any requests by this user.