Native app versus mobile website
A native app is installed from the Google Play Store or Apple App Store and runs as a dedicated application on your phone. Login persistence is typically better, push notifications work, and load times are faster on subsequent uses. The trade-off: app updates require manual download and storage space is consumed.
A mobile-optimised website works in your phone's browser. Functionality is usually identical to the desktop site, just laid out for smaller screens. No installation required, but you'll typically need to log in more often, and notifications are limited to browser-supported alerts. You can usually 'add to home screen' to mimic an app icon.
For most casual users, the difference is small. For heavy users — particularly those placing live bets where seconds matter — native apps tend to feel snappier.