APK, XAPK, and OBB Files and Mod Joy APK Hijau: A Guide for Older Android Devices

https://apkmodtracker.tearosediner.net/how-to-think-about-slow-download-problems-when-exploring-apkmodjoy

Older Android devices can still be useful, but they often need more care with app versions and resource use. APK, XAPK, and OBB labels describe different ways Android apps and large game assets may be packaged or delivered