Is CICS is necessary for a server to handle multiple clients over a network.Can't operating system alone handle this,i read in an artcle saying CICS emulates the functionality of operating system interms of multitasking to handle multiple client requests over network.
And IBM had first introduced CICS to address running several different programs for different users at the same time,till that time computers ran one program at a time
"CICS was a little operating system inside the real OS. It duplicated the usual program interfaces to manage memory, open files, communicate with remote systems, etc. However, CICS ran lots of programs in the same process address space. So there is no guarantee that two programs would not interfere with each other but CICS was able to handle thousands of n/w users."