Entity

Entity are concrete instances with unique parameters (and possibly rules) of Model. Most implementation details are defined at the Model level allowing sharing of rules and message handling.

Simply put an entity is a thing that exists in the game world (most implementation give them spatial data but this isn’t required), that can send and receive messages from other entites and other game systems.

Virtually everything is an entity… the players, the enemies, the bullets, the bonus etc. Each one has a set of properties and rules that define how it relates to other entities.