Fetch API

At a high level, fetching a resource is a fairly simple operation. A request goes in, a response comes out.

The details of that operation are however quite involved and used to not be written down carefully and differ from one API to the next. Numerous APIs provide the ability to fetch a resource, e.g. HTML’s img and script element, CSS' cursor and list-style-image, the navigator.sendBeacon() and self.importScripts() JavaScript APIs. The Fetch Standard provides a unified architecture for these features so they are all consistent when it comes to various aspects of fetching, such as redirects and the CORS protocol. The Fetch Standard also defines the fetch() JavaScript API, which exposes most of the networking functionality at a fairly low level of abstraction.