While intents map words and phrases to a specific action, entities add context to the intent itself. They help to describe the intent more fully and enable your skill to complete a user request.

The OrderPizza intent, for example, describes a user request, but only in general terms. To fill in the specifics, this intent is augmented by the PizzaSize entity, which identifies values like large, medium, and small from the user input. There are two types of entities, both of which you can declare as variables in the dialog flow: built-in entities that we provide for you and custom entities, which you can add on your own. Built-in entities match common types of information like dates, times, and numbers. Custom entities, like the PizzaSize entity example, are specific to your skill's domain.