So im pretty new to computers. I've always used them in school but this is the first one i have actually purchased and its a gaming computer. To my knowledge HDD is like my hard drive and how much storage i have. The one i bought says it has a 3 TB HDD. I downloaded 3 games (Heroes and Generals, Dirty Bomb, and CS:GO) and when i went for a fourth it said i had no more storage on my disk. Someone pls help because i dont feel like buying an external hard drive.