Digital video recorder is a digital version of a classical VCR plus something extra - when it isn't recording, it acts as a multiplexer combining all data collected by the security cameras and sending them to the server where they are safely stored.
Of course as the digital video recorder multiplexer server is the heart of all your security camera systems, it is usually a good idea to keep it someplace safe - all too often people find out that one of the first things burglars take away is their PC-based security server.
However, don't think twice about getting one - it is far too useful to just let it go.
Imagine that you do not have to check your security every single day, but you can take a look at the collected data only when you have some free time to spare.
Imagine that you can check videos taken weeks or even months ago with as little as taking the right CD from the shelf or even less as modern hard disk drives allow storing hours and hours of compressed video recordings.
And imagine that you can check the videos from another computer - if there is an Internet connection, you can monitor your home or office.
If your security system is connected to a digital video recorder multiplexer server, you won't need to use your imagination - those dreams will become reality.