Here at RubyTapas we have been searching for a good definition or discussion of entity, as the term is used in the context of domain driven design. So far the best we have found is —
“An object fundamentally defined not by its attributes, but by a thread of continuity and identity.”
— in the DDD Community Glossary of Domain-Driven Design Terms.
Wikipedia explains further with an example:
Most airlines distinguish each seat uniquely on every flight. Each seat is an entity in this context. However, Southwest Airlines, EasyJet and Ryanair do not distinguish between every seat; all seats are the same. In this context, a seat is actually a value object.
Paul Rayner has a discussion of “Aggregates & Entities in Domain-Driven Design” in his “Leading by Design” blog.
Joe Ocampo has a discussion of Entities in Domain Driven Design at Los Techies.
The Masala Chef wonders if the Head Chef might make a sideboard, or even an episode, on “Entity“, so if you want to nag us to supply better definition and/or discussion of entities, or if you want to suggest any other online references explaining “entity” (within the context of domain driven design), please submit the form below. Thanks!
— K. A. G. Sundaram, Masala Chef