Tell me about access modifiers in Java.

Asynchronous programming allows tasks to run without blocking the main thread. The application initiates an operation (e.g., network request) and continues working until the result becomes available. When the operation completes, a callback is invoked or an event is handled.

Parallelism is the ability to execute multiple tasks simultaneously. This can be achieved using multiple CPU cores, where each task runs on a separate core.

Key differences:

Characteristic	Asynchronous	Parallelism
Execution	Non-blocking	Concurrent (if multiple cores are available)
Dependency	On operation completion	On availability of computing resources
Goal	Improve responsiveness	Speed up task execution
Examples	Network requests, I/O	Data processing, computations

In Android, asynchronous operations are often used on the UI thread to avoid blocking during long tasks. Parallelism is used for heavy computations in background threads.