You can choose from two types of digital recorders as follows:PC Based SystemsA software and special board is installed on the computer so that the camera inputs will be stored on the hard drive. Using your personal computer will not do the job. Even security specialists cannot guarantee its efficiency because computer based DVR is vulnerable to software crashes, system instability, virus related problems and software crashes. Stand Alone Security Camera SystemsThe control functions and appearance of this security camera system is similar with the standard VCR recorders. System crashes can be prevented because the video processing is done by the hardware and the video in digital format is also stored in the hardware. Linux is the usual operating system that is impossible to corrupt or overwrite. The reliability and performance is far better as compared to the PC based system. Moreover, there are other factors to consider in installing security camera system. You should pay great attention to the monitoring capability of the camera. It should offer special features such as frame speed and motion detection. If you want to obtain fluent video recording, then make sure that the frame speed is higher.