Hikvision firmware is the software that controls the functionality of their devices. It's essentially the operating system of the device, managing everything from video encoding and streaming to user authentication and network connectivity. Firmware updates are crucial to:
The FTP server contains old firmware. Attempting to downgrade from V5.8.0 to V4.3.0 is generally prohibited. Hikvision bootloaders (u-boot) have a "min version" flag. Forcing an older firmware via TFTP (Trivial FTP) can permanently kill the flash memory. hikvision firmware ftp