What type of system uses cards or tags to allow for quick identification by proximity?

A proximity card system is designed specifically to use cards or tags that can be identified quickly through radio frequency identification (RFID) technology. These systems allow users to gain access simply by bringing their card or tag near a reader, eliminating the need for physical contact or insertion into a device. This quick identification method provides convenience and efficiency, making it a popular choice in many security applications.

In contrast, a keypad entry system requires users to input a specific code to gain access, which can be time-consuming and less user-friendly. Biometric systems use unique physical characteristics, like fingerprints or facial recognition, for identification, which involves more complex technology and processing than proximity cards. A magnetic stripe system, while also using cards, relies on physical contact to read the information from the strip, making it less efficient compared to the contactless nature of proximity cards. Therefore, the proximity card system stands out as the correct choice for quick identification using cards or tags.