Android App Components and Architecture

Flashcards covering key concepts from the Android lecture, including intents, services, architecture, and app components.

What is an Intent?

A messaging object used to request an action from another app component.

What are Intents used for?

Starting an activity, starting a service, broadcasting an event.

What is an explicit intent?

Specifies the exact component to start; used within the same app.

What is an implicit intent?

Does not name a specific component; declares a general action; the system finds the app to handle it.

What are the two types of services?

Started services and bound services.

What do services tell the system?

Tell the system how to manage services and keep them running until their tasks are completed.

What is a Broadcast Receiver?

A component that allows your app to respond to system-wide events even without displaying a user interface.

What is a Content Provider?

Provides access to and shares app data with other apps, granted through app permissions.

What is ART?

Ahead-of-Time compilation and is a runtime environment that executes Android apps. Native libraries are libraries written in C and C++.

What are the 5 major layers of the OS architecture?

Apps, Java API Framework, Native C++ libraries, Run time (ART), Android HAL, Linux kernel.

What benefits does Android get from the Linux kernel?

Security features like file system permissions and app sandboxing.

What is the Hardware Abstraction Layer (HAL)?

Provides device-independent interfaces to hardware components like camera and microphone.

What APIs does the Java API Framework provide?

View system, resource manager, activity manager, notification manager, content providers.

What are the four types of app components?

Activities, Services, Broadcast Receivers, and Content Providers.

What is the purpose of each app component?

Each component is an entry point through which the system or user can enter your app.

What languages can Android apps be developed using?

Kotlin, Java, and C++.

What is an Android Package?

Contains the contents of an Android app project and has a .apk suffix.

What is an Android App Bundle (AAB)?

Contains the contents of an Android app project along with additional metadata and has a .aab suffix. It is a publishing format and cannot be installed on devices.

How is Android app security implemented?

Each app has its own security sandbox, protected by Linux user IDs.