A digital camera views the scene in front of it, broadcasts the video images as a digitized signal over the internet where it is sent to a remote server. This server in turn manages all of this information. Depending upon the software used to manage the digital images, it can record, display or retransmit the images to anywhere in the world.
The software package can easily be upgraded to allow for analyzing data, selecting specific flagged items to watch for and a host of other functions, making it a truly customizable security tool.
IP-based digital surveillance uses CCD cameras that use signal processing that send packetized video streams over the LAN through a Cat 5 cable, utilizing greater bandwidth and standard IP communication. It also provides more intelligent data mining and greater ease and precision information retrieval. If security is an issue, full digital surveillance also offers the added advantage of data encryption opportunities to protect against image tampering.
Halfway there
If you decide not to use an off site server for the management and access of video images, you can maintain a Digital Video Recorder (DVR) on premises. A DVR system is not really fully IP-based, but allows you to migrate towards the more advanced IP technology. In face, a DVR system uses the same camera and structures for cabling as the older CCTV analog systems, but the old VCRs have been replaced with DVR for storage of the data. The data is converted to digital so that it can be stored on hard disks, but the quality of the images captured remains analog since this is how it originated.
When shopping for a system, ask if the system is digital based on the recording (DVR) or on the camera, since many manufacturers consider a system digital by virtue of the DVR storage system even if the camera recording the images is still analog.