Held open: A status in which the door has remained open longer than maximum set time. Can trigger an alarm.

HF(High Frequency) Card: An electronic card that operates in the 13.56 MHz band and is capable of both reading and writing data. An HF card can be fitted with various security functions, such as data encryption and allowing it to be read by a specific reader only.

HTTP: Short for Hypertext Transfer Protocol, this term refers to the protocol whereby a web client and a web server exchange data via a web browser.

HTTPS: Short for Hypertext Transfer Protocol over Secure Sockets Layer. This term refers to a protocol that provides enhanced security compared to HTTP. All data transmitted and received through HTTPS is encrypted, so HTTPS provides better security than HTTP.