Security digital video recorder or DVRs are a type of surveillance equipment which can add to your security system. You are no longer required to use video cassette tapes to ensure you have a recording of your store or home. You also do not need to download the contents of security to a disc for safe keeping because you have a security DVR that will manage it for you. If you feel it is necessary then you can record to a secondary location, but with the DVR there is a video card and hard drive that will hold numerous days of video and audio files.
If you want to have audio with your surveillance DVRs, then you will need to have cameras that support both audio and visual recording. If the camera you want doesn't have built-in audio you can usually add audio with a separate audio microphone. You may also want to consider the use of wireless transmitters since you will not need to install video cables.
By using the latest technology, you can ensure your system will protect you as well as be convenient for you. Security DVR technology has two ways it will work. You have a unit that is built directly into the camera. In this way you just need to remove the card and replace it with a new one when it is full. You do not need big monitors and additional equipment when you use this option.
If you want to you can install surveillance DVRs with TV monitors so that someone can monitor the video. It is up to you and how clandestine you feel you need to be with your security system. For example you might want to use a clock with security DVR. This type of standalone unit goes unnoticed by those who might steal in your store or home. You also have other spy cameras which offer DVR features.