Overview

Entities must have an entity type: every entity must have at least one entity type associated with it, which in turn specifies the attributes (information) that can be stored about an entity.

Entities can have multiple entity types: let's imagine you're a small business owner making jewellery, primarily selling to local members of your community. If you sell a piece of jewellery to a friend, you might represent that person as an entity in your web with multiple types assigned to them, including Person, Customer, and Friend. This lets you capture information on the entity relevant to the fact that it represnts a person (for example, that it has name), that they also represent a customer (with an order history, and lifetime value), and that they're also a friend (whose birthday, spouse's name, and other key information you might care about). Likewise, a figure like Arnold Schwarzenegger could be represented as a Person, Actor, Bodybuilder, Politician and more - and might need to be, in order to ensure that all of the relevant information about him, which you care about, can be stored. Many entities do have multiple types.

Entities can be anything: entities don't have to be people — they can be anything at all.

Representations may differ: the exact same entity represented in different users' webs may have different entity types attached to it. Not all users will care about the same aspects of an entity, so each may choose to represent it a little bit differently.