A Progressive Web App (PWA) is a type of application software that is delivered through the web and built using common web technologies such as HTML, CSS, JavaScript, and WebAssembly. It is designed to work on any platform with a single codebase and provides a user experience similar to that of a platform-specific app. PWAs can run on multiple platforms and any device with a modern web browser, and they can be located with a search engine query and accessed immediately through a browser. They are responsive and work with many different screen sizes, and they can function just like normal native apps. PWAs can take advantage of native mobile device features, such as offline mode, push notifications, cameras, and geolocation, without requiring the end-user to visit an app store, make a purchase, and download software locally. They can send web push notifications, work offline, and be accessible from the home screen, just like a mobile app from an app store. PWAs use standards-based technologies and run in a container that is secure and accessible to anyone on the web. To make sure a PWA works to its fullest potential, developers need to register and implement a service worker, which is a JavaScript file that runs in the background, enabling offline functionality, push notifications, and caching.