Why use Queueing systems such as RabbitMQ?

Question

Can someone please explain why I would use a queueing system with a small practical example?

Answer 1

I only know IBM MQ. It is used because parts of an application can work on Linux, other parts of the same application can work on windows, or any other platform (Mainframes). Because the parts of the application need to work together they need to transfer files and messages between the different operating systems. And there is also communication between different applications. Typical use is, send a message if you transferred a file from one system to another. The other system can reply if it has received and processed the file And if it went well.