How does a CICS-based application differ from a batch application?

Basic Difference

Not everything is different, of course. But here are some points to think about:

In a batch program, you often define all the required input/output and work areas within the program. In CICS, these areas are allocated by CICS, as needed, by CICS itself from a dynamic storage area within the CICS region. This lets CICS economize on main storage, and use the same copy of a program to do work for several users at once.

A batch program reads its own input data, whereas CICS reads the data on behalf of the CICS application programs. A particular CICS application program need not even be loaded into the computer before its first input message arrives.
A batch program issues its input/output instructions directly to the operating system. CICS application programs always issue such instructions to CICS, and CICS handles the interface to the operating system.