demoadmin  demoadmin This is backend user. You can use it to login backend. Also it will allow you to access Emerald control panel from user menu on frontend and some Cobalt menu elements which are only for special users such as Audit Log.
user1 user1  Simple registered user. Login this user to test subscriptions, forum and other section. This is main registered user and this one have more things then others. More subscriptions in history, more forum topics, ...
user2 user2   
user3 user3