Access control is a vital security measure that limits access to a particular area or resource to authorized personnel. It can range from basic physical barriers like lock-and-key authentication to advanced biometric-based systems like fingerprint scanners. Access control can apply to a wide range of environments from residential buildings, schools, hospitals, and offices, to military installations and government buildings.

Access control systems employ a combination of identification, authorization, and authentication to regulate access. Identification is the process of recognizing a person or object. Authorization is granting or denying access, while authentication confirms the identity of the user via passwords, ID cards, PINs, or biometric identification. Access control can help enhance security by keeping unwanted visitors away, preventing theft, and safeguarding sensitive data.