Analog cameras make use of CCD chips and turn the signals into an image that can be viewed via a television or monitor. The analog cameras have advanced well from the 1970′s and now offer high resolution, the ability to handle backlight as well as florescent light efficiently and it is now possible to monitor a whole building via the use of cabling. IP based or digital surveillance go a step further by using existng networks, offering a tremendously high resolution and also offering angle viewing. The analog cameras often had the disadvantage of blurring, costs involved with installation and maintenance. Not so when converting to digital surveillance. In some instances you can still use the analog cameras for outdoor monitoring and use the digital equipment for the rest of the building.