CICS = Customer Information Control System.
AS/400 = Older name for IBM iSeries medim size servers.
I just happen to type this nonsense while teaching myself CICS right now.
Actually right now I am learning CICS for IBM Mainframes platform, not AS/400.
I know nothing about AS/400.
The sentence is kinda war-cry I just invented to rev myself up to learn CICS ;) .
Must go back to study now.