Are asynchronous programming and multithreading related concepts, or are they separate ideas?

Asynchrony and multithreading are related but not identical.

Multithreading is the ability to execute multiple parts of a program concurrently/parallelly using multiple threads.

Asynchrony is a programming model where a task is started and does not block the main thread, waiting for completion. The main thread can perform other tasks until the asynchronous operation finishes.

Connection: Asynchronous operations are often implemented using multithreading, where long tasks are started on a separate thread so as not to block the main one. However, asynchrony can also be achieved through other means, such as event handling or using a single thread with cooperative multitasking.

Example:

• Multithreading: Two different threads perform independent computations simultaneously.
• Asynchrony: A network request is sent, the main thread continues processing the UI, and when the response arrives, special code handles the result. This request can be executed in a background thread.