A route, in the context of the WordPress REST API, is a URI which can be mapped to different HTTP methods. The mapping of an individual HTTP method to a route is known as an "endpoint". To clarify: If we make a `GET` request to `http://oursite.com/wp-json/`, we will get a JSON response showing us what routes are available, and within each route, what endpoints are available. `/wp-json/` is a route itself and when a `GET` request is made it matches to the endpoint that displays what is known as the index for the WordPress REST API. We will learn how to register our own routes and endpoints in the following sections.

[info]If you're using [non-pretty permalinks](https://wordpress.org/support/article/using-permalinks/), you should pass the REST API route as a query string parameter. The route `http://oursite.com/wp-json/` in the example above would hence be `http://oursite.com/?rest_route=/`.[/info]

One of the primary classes in the  WordPress REST API infrastructure is `WP_REST_Request`. This class is used to store and retrieve information for the current request; requests can be submitted remotely via HTTP but may also be made internally from PHP with WordPress. `WP_REST_Request` objects are automatically generated for you whenever you make an HTTP request to a registered route. The data specified in the request will determine what response you get back out of the API. There are a lot of neat things you can do using the request class. The request section will go into greater detail.