In the early days of video games, the entire game could (and indeed had to) fit into memory at the same time. However, as game data grew larger, this became impractical. So game developers found ways of making games that only use a portion of the game's full data at any one time. There are many techniques used to affect a relatively seamless loading experience. They can be divided into several categories: This has one major concern: what happens if the player happens to reach the other end of the corridor before that area is finished loading? There are several solutions: Non-video-game examples: