The Graphic engine of the R-Type project is the part which manage all things that are graphic. It’s manage with our E.C.S. (Entity Component Systems). If you don't know what an E.C.S. is, you can find an explanation here.
All these things works into a world. A World is the container for all E.C.S. data. It is the main cog of the E.C.S., it will allow you to create, store, modify and delete all the Entities, Systems and Resources of your game.