Entities:What is an entity

A Quake3 map is a collection of Entities, numbered from 0 upwards.

Some Entities can have Brushes and Bezier Patch Surfaces belonging to them.

All Brushes and Bezier Patch Surfaces belong to the Worldspawn Entity (entity 0) by default.

The Worldspawn is the solid hull around the map (the game "World"), containing all other entities within the space inside.

All entities in a map have an Origin Point and an Axis-Aligned bounding Volume (or bounding-box).

The Worldspawn's Origin is the point (0,0,0).

Each entity has a set of Properties. These properties are predefined "Keys", each Key having a variable value, which can be numerical values or a string of text.

For more information about all the entities that can be used in your map see the topic