DVRs

DVR stands for digital video recorder and refers to devices that store video digitally for later playback. The term is used for two related but distinct applications in modern media technology: consumer television recording and security surveillance. In television, a DVR is often a stand-alone box or a set-top device that records broadcast programs onto a hard drive, enabling features such as pause, rewind, fast-forward, and time shifting. In security, a DVR is a dedicated recorder that accepts video input from multiple cameras and stores footage for review and evidence.

Television-oriented DVRs typically connect to a home network or directly to a television system. They rely on electronic program guides for scheduling recordings and may offer variable storage capacities, depending on the installed hard drive. Common formats for recorded video include MPEG-2 and MPEG-4, with modern models sometimes supporting advanced codecs and higher-definition content. Some DVRs also function as media servers, enabling playback of stored content on connected devices.

Security-oriented DVRs receive video signals from analog CCTV cameras, usually over coaxial cables. They compress and store footage on internal or attached hard drives and provide search tools, motion detection, and time-stamped playback. Network connectivity enables remote viewing through local networks or the internet, often via web or mobile apps. Many systems support multiple drives, RAID configurations, and integration with other security components.

Over time, competing architectures have emerged. DVRs primarily handle analog sources, while network video recorders (NVRs) process IP cameras. Hybrid models exist that support both analog and IP inputs, reflecting the transition toward IP-based surveillance.