The primary goal of an ECS is to provide fast access to many entities; especially where those entities share many of the same properties. It also solves issues regarding adaptability in an inheritance-based engine.
ECS is more of a conceptual idea rather than an actual engine structure. There exists many variations of the concept, each adding in different features and models as required.
1. The **entity**, which is a simple ID, usually an index.
2. The **component**, which is a struct or class that stores data
3. The **system**, which is a functionality that is executed regularly by the engine.
4. The **engine** (*sometimes split into parts called 'managers'*), which controls the interaction between these components, and provides access to the external program.
## About JavaECS
The focus of JavaECS is more about the structure rather than raw performance. It remains performant, but there may be multiple areas where improvements can be made.
In a quick port of Alex Beimler's [ECS Benchmark](https://github.com/abeimler/ecs_benchmark), JavaECS performs at about the same speed as [ECS](https://github.com/redxdev/ECS) (~90 ms). The results aren't normalised between test environments, so take them with a grain of salt; but it tends to suggest that the project has decent performance.
