Android devices और OS versions की विशाल श्रेणी ("fragmentation") पर चलता है, इसलिए ऐप्स को version compatibility को संभालना होगा — नई features को सुरक्षित रूप से उपयोग करते हुए पुराने versions का समर्थन करना। SDK levels, compatibility libraries, और graceful degradation को समझना महत्वपूर्ण है।
SDK levels: 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).
