There are certain applications for surveillance and security where a "standard" Digital Video Recorder or DVR is just too large. For these applications the best choice is a micro DVR. Micro DVRs can be so small as to fit inside the casing of an ink pen. Let's take a look at a digital video system that uses standard size DVRs first, and then take a look at micro DVRs.
A standard DVR is about the size of DVD player. The front of the DVR has buttons and switches to control the actions of the DVR. The back of the DVR is where all the connections are made to cameras and other items.