What type of Operating System (OS) does the Security DVR use?

Most PC-based Security DVR Systems use Windows 7 Professional, and Standalone Security DVRs are Linux based.with some of the software that can detect and clarify images or we can say multimedia coding provided programs , like face detection or license plate detection ....

PC BASED Window OS DVR CAN BE USE , Win XP , Windows Server , WIN7 , VISTA & WINDOW

Non OS Window LINUX & MAC ( Since linux & Mac has open source DVR Software )

Stand Alone DVR , Router , Ip Camera , android handphone , Access Control , Cisco , Network Attached Storage, Digital PABX , Managed Switch ,  Router , Mikrotik & Mifi Router use Linux as their based operational system and it has opening TCP port and to managed it.

ubuntu/ linex  are the best for security than any other operating system

Most PC-based Security DVR Systems use Windows 7 Professional, and Standalone Security DVRs are Linux based.

it use application software.

I would say that majority of manufacturer develop their own operating systems for their DVR/NVR systems but most are based on Linux.

Windows 7 and standalone security DVRs basically Linux

the tyoe of operating system of a dvr is dedicated operating system which means a specific software for a specific device only

Mostly they run on Windows 7 or above, and some on linux

 major players is Linux based DVR i.e. -DOM DVR: VPON in Taiwan, working with their own software compression cards. Softwell in Taiwan, working with their own software compression cards. Linovision in China, working with hikvision DSP hardware compression cards. 

Windows 7 or More and some standalone DVR's use Linux