Illuminance is intensity of light received by a certain aspect, and the speed of incident light per unit area. The unit uses Lux. 

Health Check checks the status of the server or network operating normally, just like performing a medical checkup before a person is sick. Certain rules with predetermined answers are executed to check the presence or absence of disability, and if necessary, disability units are separated. 

H.265 codec gives more efficient file size than previous H.264 to save storage and bandwidth. Also to have interoperability with legacy systems, built-in H.264 provides compatibility with H.264 mandatory RX systems. 

Horizontal Resolution refers to the spatial resolution in the horizontal direction, and is a criterion indicating to what extent the detailed part of the subject can be reproduced. 

Fail Back returns a system automatically switched to failover to its existing state.