State, Property, and Condition

Definitions

Property

A characteristic or feature of an entity that is observable, measurable, or otherwise determinable.

Condition

The value of a property of an entity at a given time that is observable, measurable, or otherwise determinable.

State

The complete set of conditions that describe an entity at a specific moment in time.

X: Entity

X is any entity that can have a state and conditions.

Examples of X

• A person
• A group
• A car
• A computer program
• A place
• A machine
• An organization
• An animal

Clarifying: Property vs. Condition

• A property is a general characteristic of an entity. It exists regardless of time.
  • Example: temperature, battery level, position, heart rate.
• A condition is a property with a specific value at a specific time.
  • Example: “battery level = 84%”, “temperature = 72°F at noon”, “status = offline”.

All conditions are time-bound expressions of properties.
Not all properties are conditions until they are assigned a value in time.