Security cameras are either digital or analog. Security cameras work by sending analog or digital signals to a storage device such as a DVR device, desktop computer, or laptop computer. Security cameras can record analog signals as images. These are recorded directly to a DVR device. Analog signals are recorded on tape, and then the tape needs to run at a very slow speed to allow continuous operation. To allow a three-hour tape to run for 24 hours, it must be set to run with a time-lapse of about one second every four frames. Because one second can significantly change the image in the camera. Security camera analog signals also need to be converted into digital signals to allow storage on a PC, such as digital recordings. In this case, the analog video camera needs to be directly plugged into a video capture card (DVR card) in the computer. These cards are relatively inexpensive, but the resulting digital signals need to be compressed to 5:1 (MPEG compression) for continuous video recording. There is another way to store recordings on a non-digital analog medium. This involves the use of a digital video recorder (DVR recorder). The functionality of such a device is similar to a PC with a capture card and appropriate video recording software. Unlike computers, it is designed for CCTV cameras. DVR recorders require less maintenance and are simpler to install compared to PC-based solutions. Looking at the contents of a network camera. From left to right: network adapter, power supply, processor, image encoder, image sensor. IP cameras or network cameras are analog or digital video cameras, plus they have an embedded video server with an IP address capable of streaming video (and sometimes, even audio). Network cameras also do not require devices and analog signals, so higher resolution is possible with analog CCTV cameras. Network cameras typically have resolutions of VGA (640 × 480 pixels), SVGA (800 × 600 pixels), or quad-VGA (1280 × 1280 pixels), while a typical analog CCTV camera has PAL (768 × 576 pixels) or NTSC (720 × 480 pixels). Also, there is audio. Analog or digital cameras connected to a video server behave like network cameras, but the image size is limited by the camera's video standard. However, it is the optical components (lenses and image sensors), not the video resolution, that determine image quality. IP CAMERAS offer advantages over analog cameras in terms of price-performance; network cameras are competitive products in the CCTV sector because they offer better performance than network cameras at a lower price than analog cameras.