Entities

What are entities?

Entities are individual “things” with a distinct, independent existence.

Every entity in HASH has:

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  a HASH ID, which makes it uniquely identifiable and content-addressable;

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  one or more entity types which describe the entity’s expected properties;

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  properties, infered from its entity type(s), which may in turn contain values.

The entity type tells you what kind of thing an entity is expected to be (e.g. a Book, which is expected to have properties such as author, title and publisher).

The values of an entity’s properties tell you about that instance of the entity itself, for example what its title actually is (e.g. “Brave New World”).

Sometimes the values of a property may contain links. In such cases, we would describe an entity as a linked entity.

What are linked entities?

In the real world, entities are often connected to other entities, and these connections are described as relationships.

Sometimes these connections take the form of social relationships (e.g. “Mother", "Child”, or “Friend") occurring between entities of the same [entity type] (in this example Person).

However, entities of completely different entity types can also be linked. For example, connections between entities may sometimes be legal or procedural, such as “Employee <> Employer” or “Politician <> Political Party”, which may both link a Person with an Organization.

A network of entities which are connected to other entities is sometimes called a graph or a web (in HASH). We call these entities with links ‘linked entities’.

Are entities the same thing as 'agents'?

If you’re using our advanced HASH for simulation platform, you might be wondering about the relationship between entities and agents. For all practical purposes, you can think of both as the same thing. In future releases of HASH Core and HASH Engine we’ll support instantiating entities from a HASH workspace directly within simulations (as agents), as well as assigning expected behaviors to entity types in HASH.