If you’re “Basis/Technical”, focusing on the underlying technical “Basis” or “NetWeaver” versions will help you stay on the right track. Technically, ECC 6.0 is 2 “technology” versions higher. Following is the terminology/version information for the last 3 ERP product versions:
SAP R/3 Enterprise (4.7x)
SAP BASIS 6.20
SAP ERP 2004
SAP NetWeaver 2004 (BASIS 6.40)
SAP ERP 2005
SAP NetWeaver 2004s (BASIS 7.00)
The main technology feature delivered with NetWeaver is the integrated J2EE engine (Web Application Server Java).
For Functionality Differences pls refer to the below site –
After opening the site, please select the Source Release Version which is 4.7 Then Select the Target Release Version which is “mySAP ERP 2004″ or ECC 5.0
or “mySAP ERP 2005″ or ECC 6.0
Select the Solution Area like Sales….
Select module like SD…….
Click on Search
Then it displays the Release Version and the Delta Functionality. which can be downloaded to a word document if required.
and also check the release notes of ECC 5.0 & ECC 6.0 in service.sap.com.
Hope that helps!