The functions of hip seat n ssc is it the same?

SSC refers to Soft Structured Carrier. A hip seat refers to a carrier with a base like a stool to support the baby. An ergonomic soft structured carrier will not come with a hip seat as hip seat is not suitable for young babies and not ergonomic for the wearer. The seat, being positioned further away from the wearer would be pulling on your back rather than helping to distribute the weight more evenly.