What is the difference between synchronous and asynchronous interaction, and in which cases is each better to use?

Synchronous interaction implies that the calling process waits for the operation to complete and the result to be received before continuing its work. Asynchronous interaction allows initiating an operation and continuing execution without waiting for its completion; the result is processed later, for example, through callbacks, events, or message queues.

When to use synchronous interaction:

• When execution order is important and the result is needed immediately.
• In simple scenarios with low latency.

When to use asynchronous interaction:

• To improve performance and scalability, especially when working with slow or external services.
• In high-load systems where blocking threads is not allowed.
• To implement event-driven architecture.

Example: In a web application, a database query can be asynchronous to avoid blocking the UI, while a function call that needs to return a result for further calculations is synchronous.