This document is designed to provide guidance to assist in understanding the OCC's authority to supervise both national banks and federal savings associations. It is not meant to provide a comprehensive analysis of all the regulations or policies applicable to or the powers of these institutions, but rather to provide a brief guide to some of the key differences. The guide contains references to relevant statutes and regulations, including OTS regulations reissued as part of the Code of Federal Regulations codified at 12 CFR 100-199.