Do you mean simultaneous games? (AKA simul, i.e. Hey, I will simul you guys) Simultaneous games are when a person plays several games at once versus many or one person, which on chess.com is easy to do for the most part due to the large amount of time a person has to make a move. As the number of simultaneous games increases, the level of difficulty increases as well due to the need of more concentration. I don't know what a simulated game would be except the act of a game that was simulated.
Simulated Games?
If you are asking about the number of simultaneous games played in a tournament go to any tournament page and look to the right for the Help link. From there you will find this description of tournament formats.
i'm not understanding what this means... some have 10 some have 20+... can it be explained to me? yes.. i'm that dumb.... thx!