The SharedWorker interface represents a specific kind of worker that can be accessed from several browsing contexts, such as several windows, iframes or even workers. They implement an interface different than dedicated workers and have a different global scope, SharedWorkerGlobalScope.
The port property of the SharedWorker interface returns a MessagePort object used to communicate and control the shared worker.
The SharedWorker() constructor creates a SharedWorker object that executes the script at the specified URL. This script must obey the same-origin policy.