A network camera can be described as a camera and computer combined into one unit. It connects directly to the network as any other network device. A network camera has its own IP address and built-in computing functions to handle network communication.
Everything needed for viewing images over the network is built into the unit. A network camera has built-in software for a Web server, FTP server, FTP client and e-mail client. Other features include alarm input and relay output functions. More advanced network cameras can also be equipped with many other value-added options such as motion detection and an analog video output.
The lens of the camera focuses the image onto the image sensor (CCD/CMOS). Before reaching the image sensor, the images pass through the optical filter, which removes any infrared (IR) light so that the "correct" colors will be displayed.
The image sensor converts the image, which is composed of light information, into electrical signals. These electrical, digital signals are now in a format that can be compressed and transferred over networks.
The CPU, Flash memory and DRAM memory represent the "brains" or computing functions of the camera and are designed specifically for network applications. Together, they handle the communication with the network and the Web server.
Via the Ethernet port, a high-end network camera can send images directly to 10 or more computers simultaneously. If the images are first sent to an external Web server (instead of directly to the viewers), real-time video can be seen by an unlimited number of viewers.