What is service worker in pwa?

Question

I heard the term "worker thread" and other types of threads such as "system thread" and "user thread".
For me a thread is nothing but a lite weight process and multi-threaded design is chosen for a software development when there are multiple task in the application/system and those tasks can be executed independently.
I want to know when these different terms are used like worker thread, user thread and system thread ?

Answer 1

Service workers are at the core of PWA techniques for resource-caching and push notifications.A Progressive Web App (PWA) is a term Google coined to describe its prospect of app-like web experiences, in which web pages are able to offer many features once deemed app-only — connectivity control, push notifications, home screen icons etc.