List the key concepts of Progressive Web Apps:

PWAs work for all users, regardless of their device or browser.

They provide a baseline experience and progressively enhance it for browsers that support advanced features.

PWAs are designed to work seamlessly across different screen sizes and orientations.

PWAs provide a smooth and app-like experience, including smooth animations, gestures, and interactions.

PWAs can function even when the user is offline or has limited connectivity.

They cache content and data, allowing users to access the app even without an internet connection.

PWAs can send push notifications to users, keeping them engaged and informed even when the app is not open.

PWAs load quickly, ensuring a snappy experience for users, reducing bounce rates, and improving engagement.

Users can add PWAs to their home screen or app launcher, giving them easy access without going through an app store.

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