Basic SAP differences
- Unicode was used from ECC 5.0 and upwards, Upto SAP 4.7 – Nonunicode was used.
- 4.6C has ABAP stack, 5.0 and 6.0 have netweaver component (Java is additional)
- For installing SAP ECC6.0 Solution Manager Key is required. Previously it was not required
- Features and configurations were done using the tables directly, in ECC5.0 and upwards, it is dont using the IMG nodes.
- Integration with SOA was possible after ECC6.0
Check functionality-wise differences in this link