A website that can feel like an app
A progressive web app (PWA) opens from a web address. You may also be able to install it from your browser, giving it an icon and its own window. Some PWAs can show saved content without an internet connection or send notifications.
A web app manifest provides the name and icon. A service worker helps save website files on your device so parts of the app can work offline. New content from the website still needs an internet connection.
The service worker is a browser feature with a different job from a web worker, which handles calculations away from the page.
Features depend on your device
“Progressive” means the basic website should still work when an extra feature is unavailable. Installation, offline access, and notifications vary by browser and device.