Platform video games are video games wherein players control a character by jumping or otherwise operating on physical (virtual) platforms. Mario and his impressive jumping abilities are pretty much the defining trend of the genre. Gameplay tends to be simplistic, usually involving only one or two dynamics for using the character to solve puzzles or defeat enemies.
3D platformers, or three-dimensional platformers, are 3D games which emphasize platforming mechanics, whether in first-person or third-person view. Some can suffer from camera problems, as the genre, which encourages obstacles surrounding the player, is not always friendly to an external camera object.