What are the similarities and differences between synchronous and asynchronous in Java?

1. Synchronous interaction: Refers to sending a request, need to wait to return, and then be able to send the next request, there is a wait process;

2. Asynchronous interaction: Refers to sending a request, without waiting for a return, at any time to send the next request, that is, no wait. Difference: one needs to wait, one does not need to wait, and in some cases, our project development will prioritize the asynchronous interaction that does not need to wait.

3. What are the recommended scenarios for using synchronous interaction? For example, the bank's transfer system, the preservation of the database operations, and so on, will use synchronous interaction, the rest of the situation is preferred to use asynchronous interaction.

What are the similarities and differences between synchronous and asynchronous in Java?