Smart locks use a variety of technologies to allow users to remotely control and monitor access to their homes or businesses. Some smart locks use Bluetooth, Wi-Fi, or Zigbee to connect to a smartphone app, while others use a keypad or RFID card reader to grant access. Once connected, users can lock and unlock the door remotely, set up access codes for family members or guests, and receive notifications when someone enters or leaves the premises. Some smart locks also integrate with other smart home devices, such as security cameras or voice assistants, to provide a more comprehensive home automation experience.