The credential can take various forms, including physical keys (in rudimentary systems), access cards (prox card, smart card), key fobs, PIN codes, or advanced biometric identifiers such as fingerprints, facial recognition, or iris scans. When a credential is presented at a reader located at an entry point (e.g., a door, turnstile, gate), the system checks its validity against a centr... https://guardworkforce.com.sg/access-control-system/