Bob is what they call a defender. He protects the system from viruses like Hexadecimal and Megabyte. In their world games come and go in the system, and if the defender loses the game, it starts tearing apart the system. The more they lose, the more the system becomes a ruin. As a guardian, Bob is required to play the games.
Dot is one of the leaders of Mainframe, the system which they inhabit.
She sets of the scramble alarm to their squadrons, alarming them when the viruses invade, or other disasters. Enzo is an enthusiastic boy who really wants to help Bob, and be like him. Frisket is Enzo's pet, and he does everything he can to help Enzo. He has an iron hard bite, and not much patience when it comes to viruses. Hexadecimal is an insane virus, who has a certain fondness for Bob.