What is asynchrony and parallelism in the context of application development?

Asynchrony is a programming model that allows tasks to be performed without blocking the main thread. The application initiates an operation (for example, a network request) and continues to work until the result becomes available. When the operation completes, a callback is invoked or an event is handled.

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

Key differences:

Characteristic	Asynchrony	Parallelism
Execution	Non-blocking	Concurrent (if cores are available)
Dependency	On operation completion	On availability of computational resources
Goal	Improving application responsiveness	Speeding up task execution
Examples	Network requests, input/output	Data processing, computations

In the context of Android, asynchrony is often used for the UI thread (Main thread) to avoid blocking during long operations. Parallelism is used for executing heavy computations in background threads.