Access control simply defined, refers to the process of managing information and equipment to determine who, when and where personnel and materials may enter and exit.

A properly configured access control system allows the movement of authorized personnel and materials into and out of facilities, while detecting and delaying unauthorized personnel and materials. Access control points should be located at a facility boundary or perimeter, such as at vehicle gates, building entry points, pedestrian and freight elevators, secured and special use rooms or other special areas within a facility. The objectives of an access control system are;

• To detect, deter and facilitate a response to potential threats to both property and people.
  
• To permit only authorized persons to enter and exit a facility.
  
• To detect and prevent the access of unauthorized personnel or materials.
  
• To detect and prevent the entry or exit of unauthorized materials.
  
• To provide information to security personnel to facilitate the appropriate assessments and responses.

These objectives can be met with a simple brass key or with a complex mixture of biometrics, credentials, personnel identification numbers and surveillance equipment.