In transaction SM21 (the system log), what does each message colour indicate?

Which transaction shows the work processes of the instance you are logged on to?

What is the role of the message server in an SAP system?

What are the possible status values of an application server instance in SM51?

What is the difference between cancelling a work process "with core" versus "without core"?

Which transaction displays operating-system and hardware metrics (CPU, memory, disk, swap) for an SAP instance, and what gathers its data?

In SM50, what is the difference between a work process with status **Waiting** and one with status **Running**?