When you are looking into surveillance cameras and Digital VIdeo Recorders (more commonly known as DVRs) there are a wide variety of units available on the market. They will range from the most basic units that only record 4 cameras at CIF resolution all the way up to 32 cameras that record at D1 resolution. If you need higher resolution there are recorders known as NVRs or network video recorders, these units can record video up to 1080p resolution. Not everyone will want to spend the money to step up into Network Video Recorders (more commonly know as NVRs) with IP cameras especially if they have existing analog cameras. However there are units out there that will allow customers to keep their existing cameras and add IP cameras all on the same unit. There are several benefits to a system like this. These units are commonly known as Hybrid DVRs, the name comes from the unit actually being a combination (hybrid) of a full size DVR and a mini NVR.