changes that are to be made.
changes can be done in the current version or in he next 
version

Enhancement is one with which we can add our own 
fucntionality without modifying the standard program 
provided by SAP according to the business needs.

There has not been any problem for enhanced code for SAP 
newer version releases.

enhancement means adding some functionality to the standard 
program
for this first go to CMOD find the user exit and in that 
user exit make the changes in the include program provided 
by sap

R/3 ENHANCEMENT concept allows us to add our functionality 
to SAP's standard business applications WITHOUT HAVING TO 
MODIFY the original applications.
SAP creates enhancements for specific PROGRAMS, SCREENS AND 
MENUS within standard R/3 applications. These enhancements 
do not contain any functionality, instead act as HOOKS 
WHERE WE can HANG our own ADD-ON functionality onto these 
hooks.

Advantages with Enhancements:
1.> They do not affect standard SAP source code.
2.> They do not affect software updates.

NOTE: Customer enhancements may not be available for all 
programs and screens found in SAP system. YOU CAN ONLY USE 
CUSTOMER EXITS IF THEY ALREADY EXISTS IN THE SAP SYSTEM.

Enhancement Approaches:
1.>Procedural approach using Function Modules and are 
called as Customer Exits .
2.>Object Oriented approach using Classes & Methods & are 
called BADI's.