You have several types of servers at your disposal, which can perform specialized tasks.
Examples would be:
A server can accept the requests of several clients and process them in the FiFo principle (also other principles).
The server is the link between the clients and the processing logic.
If a server experiences faults due to incorrect configurations, unsuitable data or similar, it can attempt to deal with these faults within the scope of its configurations and validations. If this is not successful, a client can request a reset of the server.
If you need redundancy, load balancing or parallel processing, multiple servers can be configured as a group.