Guest is a special account that doesn't have a profile in C:\Users and it's generally disabled. There is also a built-in Administrator account which is also disabled by default. Public is not really a user, but items added in that folder are available to all users and it requires admin rights to modify. If you are looking at the computer remotely you may not be able to even see user "Holly" unless specifically given Read rights to it, or it has to do with the way homegroups work which isn't something I'm very familiar with. That or Holly is just the display name and "Owner" is really the account