Quick rant: it's "Entity Component Systems". The "System" doesn't describe the approach in general, it describes an object called a "System". Entities are IDs (

Quick rant: it's "Entity Component Systems". The "System" doesn't describe the approach in general, it describes an object called a "System". Entities are IDs (equivalent to indexes into his array), Components are property bags (values in his array), Systems are things that act on components (his update loop could be considered a System). The idea behind it is that you can have a "WorldPosition" Component which stores all world positions as a flat array, and a "Gravity" System which acts upon WorldPosition components and makes them move. The idea is that since your data is tightly packed, it's easier to update. A lot of people get this confused, though, so no worries.