Entity Basics
From Mod Wiki
Entity types
Point-based
Point-based entities have a fixed size, but can have their location and orientation changed.
Examples of point-entities include light, info_player_start and moveable_item_ball.
Brush-based
Brush-based entities take their shape from one or more brushes, and similarly, can also have their location and orientation changed. They are typically used to make brushes move, change state, or to indicate areas (that are invisible in-game)
Examples of brush-entities include func_door, trigger_multiple and bot_action_bbox.
