An entity is the blank container that every game object in GBS consists of. An entity can hold whatever components you need to make up the characteristics of your game object.
You can think about an Entity as a container for building blocks or legos.
Components / Building Blocks
You pick from our list of components / building blocks and add then to an entity until you come up with a car or an animated character or a building, etc.
In GameBuilder Studio you edit your entity in the properties panel by adding different components to it to define its functionality and look and feel. Also an entity has to have a unique name, so that it can be referenced directly when needed. More on this later.