In addition to the new kernel-based BAdI, there are many other types of enhancement options that are part of the new Enhancement Framework. You implement these enhancements using the Enhancement Framework tools, which are integrated into the ABAP Workbench
In all the aspects, enhancements are more powerful than modifications, even given all the modification support that transaction SPAU offers. The reason is due to an important difference between an enhancement and a modification that stems from the conceptual difference between the two technologies.
In contrast to enhancements in the Enhancement Framework, modifications are physically part of the object they modify. This means that every single modification gets lost in an upgrade and needs to be re-inserted even in cases where the underlying SAP object has not changed at all!
SAP NetWeaver 7.0 (formerly 2004s) offers the new Enhancement Framework that not only is intended to unify the modification and classic enhancement techniques, but also offers you almost the same flexibility as modifications without the limitations of modifications.
With all their new features, the latest versions of the ABAP Editor, I thought it best to appreciate the new features; we should first go back in time to see some of the limitations that were present in prior versions of the editor.