Sometimes, our internet connection isn't reliable or completely absent. In those moments, we still want to use websites and apps. This is where offline web pages come in handy. They allow us to access content even when we're not online.
Service Workers are like web helpers. It work behind the scenes to make offline web pages possible. It can save website stuff (like pictures, fonts and other assets) on our device so we can see them even without the internet. It also control what our web page does when it's online.
Cache Storage is like a storage room for web things. It keeps all the website stuff we might need, organised neatly. Service Workers can go there and grab what's needed for page to load offline. So, when we're not online, we still get to see and use web pages.
Read this article to learn how to make a webpage available in offline