| App Structure | Structure of an Android project, including important directories. | src/, res/, AndroidManifest.xml |
| Activities | Represents a screen in an app; controls UI interaction. | Activity, Intent, onCreate(), onStart(), onResume() |
| Views & Widgets | UI components like buttons, text fields, images. | TextView, Button, ImageView, RecyclerView, EditText |
| Layouts | Defines how views are arranged on the screen. | LinearLayout, RelativeLayout, ConstraintLayout |
| Intents | Used for communication between components (e.g., starting activities). | Intent, BroadcastReceiver, PendingIntent |
| Resources | Store application resources such as strings, images, and colors. | res/, strings.xml, drawable/, values/colors.xml |
| Permissions | Manage app permissions for accessing device features. | AndroidManifest.xml, checkSelfPermission(), requestPermissions() |
| Storage | Data storage options for saving and retrieving data. | SharedPreferences, SQLiteDatabase, File, ContentProvider |
| Networking | Communication with external servers and APIs. | HttpURLConnection, Retrofit, Volley, OkHttp |
| Background Tasks | Perform tasks in the background (e.g., downloading data). | AsyncTask, Handler, ExecutorService, WorkManager |
| Fragments | Reusable UI components that can be combined within an activity. | Fragment, FragmentTransaction, FragmentManager |
| Services | For long-running operations in the background (e.g., music playback). | Service, IntentService, JobIntentService |
| Broadcast Receivers | Listen for and respond to system-wide broadcast announcements. | BroadcastReceiver, sendBroadcast(), LocalBroadcastManager |
| UI Thread & Handlers | Manage UI updates and tasks in the background. | Handler, Looper, runOnUiThread(), MessageQueue |
| Notifications | Display notifications to users outside the app’s UI. | Notification, NotificationManager, NotificationChannel |
| Testing | Tools for testing Android applications. | JUnit, Mockito, Espresso, Robolectric |
