Access control is a method of limiting access to a system or to physical or virtual resources. It is a process by which users can access and are granted certain prerogative to systems, resources or information. Access control is a security technique that has control over who can view different aspects, what can be viewed and who can use resources in a computing environment. It is a fundamental concept in security that reduces risk to the business or organization. To establish a secure system, electronic access control systems are used that depend on user credentials, access card readers, auditing and reports to track employee access to restricted business locations and areas. These systems include access control panels to prohibit entry to sensitive areas like alarms and lock down areas to prevent unauthorized access or operations. Access control systems perform identification, authentication, and authorization of users and entities by evaluating required login credentials that may include passwords, pins, bio-metric scans or other authentication factors. There is multi-factor authentication which requires two or more authentication factors which is often an important part of the layered defense to protect access control systems. Authentication Factors:Password or PINBio-metric measurement (fingerprint & retina scan)Card or Key