• Electronic locks restrict access to authorized personnel.Don Farrall/Photodisc/Getty Images
  
  Security and access are major considerations in many business and government facilities. Different types of electronic locks can allow easy access for authorized personnel while keeping everyone else out. The earliest form of electric locks used electromagnets to keep doors locked. Newer electronic locks integrated with access control systems use card swipe or keypad locks to limit access to authorized personnel. Other electronic locks make use of biometric scanners such as fingerprint readers and retinal scanners.
  
  

Smart Card Locks

• Locks requiring a coded card key to open them are common fixtures in factories, office buildings and hotels. In hotels the card keys are programmable, so they are unique to the guest while registered in the hotel. After check out, the access system is changed to prevent the card from opening the door. This prevents access to hotel rooms using lost or stolen key cards.
  
  A common method of controlling access in commercial buildings is combining the card key with employee identification cards. According to the Smart Card Alliance, an industry association, the card contains an integrated circuit chip that can interact with the door card reader.
  
  

Proximity Scanning

• Another type of electronic lock uses proximity scanning. The lock contains a scanner that reads the radio frequency signal generated by the smart card or other access device. Plastic ID cards, USB access tokens and certain subscriber identity module cards, or SIM cards, for cellular phones can interact with the lock.
  
  A common use for this technology is in factories and office buildings where employees must pass their company ID badge over a scanning plate to gain access into the building. This type of electronic lock access is also used to permit access into secure parking areas. Authorized vehicles carry a tag that interacts with the lock sensor to open the entryway to the parking area.
  
  

Hand Key Locks

• A hand key lock is a biometric device that reads your hand print to open a door. This kind of access control device is cost effective because there is no need to replace cards keys that can be lost or stolen. Your hand is your key.
  
  Hand key readers can be programmed to work as stand alone units or as an integrated part of an access control system. According to Global Security, a security development organization, the device stores a two-dimensional image of the hand geometry with more than 90 dimensional measurements. This system has also been used in airports to speed up the customs identification process.