Android berjalan pada julat peranti dan versi OS yang besar ("fragmentasi"), jadi aplikasi mesti mengendalikan keserasian versi — menyokong versi lama sambil menggunakan ciri baharu dengan selamat. Memahami tahap SDK, pustaka keserasian, dan degradasi yang anggun adalah penting.
Tahap SDK: min, target, compile
minSdk → the OLDEST Android version the app supports (older devices can't install it)
→ lower minSdk = more devices reached, but more compatibility work
targetSdk → the version the app is TESTED/optimized against (and opts into its behaviors)
→ should be kept current (Play requires a recent targetSdk)
compileSdk → the SDK version used to COMPILE (access to newer APIs)
→ Balance: support enough old devices (minSdk) while targeting current behavior (targetSdk).
