| Package / Class | Purpose |
|---|
| android.app.Activity | Single screen UI with lifecycle management |
| android.app.Fragment | Reusable portion of UI |
| android.app.Service | Background operations without UI |
| android.content.BroadcastReceiver | Receive system broadcast events |
| android.content.ContentProvider | Share data between applications |
| android.content.Intent | Inter-component communication message |
| android.view.View | Base class for UI widgets |
| android.widget.TextView | Text display widget |
| android.widget.RecyclerView | Efficient list/grid display |
| android.database.sqlite.SQLiteDatabase | SQLite database management |
| Term | Definition |
|---|
| Activity | A single, focused task the user can do |
| ADB | Android Debug Bridge — CLI tool for device communication |
| APK | Android Package Kit — app installation file |
| ART | Android Runtime — runs app bytecode |
| AAB | Android App Bundle — publishing format |
| DP / DIP | Density-independent pixel |
| Fragment | A portion of UI in an Activity |
| Gradle | Build automation system for Android |
| Intent | Message to request an action from another component |
| MVP / MVVM | Architecture patterns for organizing code |
| ProGuard | Code shrinker and obfuscation tool |
| SDK | Software Development Kit |
| SP | Scale-independent pixel (for fonts) |
| ViewModel | Stores UI-related data across config changes |