This document provides an overview of access control models and methods. It defines access control as the interaction between a subject and object allowing information flow. It describes Mandatory Access Control (MAC) and Discretionary Access Control (DAC) models, and Role-Based Access Control (RBAC). Centralized and decentralized administration methods are also outlined. Common security models like Bell-LaPadula, Biba, and Clark-Wilson are briefly explained. Authentication methods and types of access attacks are listed.