What are the differences between methods that support the use of coroutines and those that are not designed to work with them?

Methods that support the use of coroutines differ from regular methods in that they can suspend their execution and resume it later without blocking the thread. In Java, this is implemented, for example, through asynchronous methods using CompletableFuture or libraries that support coroutines (such as Kotlin Coroutines).

Main differences:

• Suspension and resumption: Coroutine-supporting methods can "freeze" their state and resume execution, allowing asynchronous code to be written in a synchronous style.
• Non-blocking execution: Such methods do not block the thread but free it for other tasks.
• Special syntax or API: Working with coroutines often involves special syntax (e.g., suspend in Kotlin) or APIs that allow managing the execution state.

Unlike them, regular methods execute to completion immediately, blocking the thread if there are long operations inside.