olemus
JavaScript-skript, mis täidetakse HTML-lehel muudest skriptidest sõltumatult, näiteks arvutuste tegemiseks
= a dedicated JavaScript script that runs in the background

ülevaateid
https://en.wikipedia.org/wiki/Web_worker
https://www.educba.com/html5-web-workers/
https://medium.com/young-coder/a-simple-introduction-to-web-workers-in-javascript-b3504f9d9d1c
https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Using_web_workers
https://www.html5rocks.com/en/tutorials/workers/basics/
https://w3c.github.io/workers/