Webcam

Webcams (web cameras) are small cameras (usually, though not always, video cameras), whose images can be accessed using the World Wide Web, instant messaging, or a PC video conferencing application.

Web-accessible cameras involve a digital camera that uploads images to a web server, either continuously or at regular intervals. This may be achieved by a camera attached to a PC, or by dedicated hardware. Videoconferencing cameras typically take the form of a small camera connected directly to a PC. Analog cameras are also sometimes used (often of the sort used for closed-circuit television), connected to a video capture card and then directly or indirectly to the internet.

Web-accessible cameras

In addition to use for personal videoconferencing, it was quickly realised that World Wide Web users enjoyed viewing images from cameras set up by others elsewhere in the world. While the term "webcam" refers to the technology generally, the first part of the term ("web-") is often replaced with a word describing what can be viewed with the camera, such as a netcam or streetcam. Educators can use webcams to take their students on virtual field trips.

Today there are millions of webcams that provide views into homes, offices and other buildings as well as providing panoramic views of cities (Metrocams) and the countryside. Webcams are used to monitor traffic with TraffiCams, the weather with WeatherCams and even volcanoes with VolcanoCams. Webcam aggregators allow viewers to search for specific webcams based on geography or other criteria.

Videoconferencing

As webcam capabilities have been added to instant messaging text chat services such as AOL Instant Messenger, one-to-one live video communication over the internet has now reached millions of mainstream PC users worldwide. Increased video quality has helped webcams encroach on traditional video conferencing systems. New features such as lighting, real-time enhancements (retouching, wrinkle smoothing and vertical stretch) can make users more comfortable, further increasing popularity. Features and performance vary between programs.

Videoconferencing support is included in programs including Yahoo Messenger, AOL Instant Messenger (AIM), Windows Live Messenger, Skype, iChat, Paltalk (now PaltalkScene), Ekiga , Stickam, and Camfrog.

Some online video broadcasting sites have taken advantage of this technology to create internet television programs centered around two (or more) people "diavlogging" with each other from two different places. Among others, BloggingHeads.tv uses this technology to set up conversations between prominent journalists, scientists, bloggers, and philosophers.

Video security

Webcams are being used for security purposes. Software is available allowing PC-connected cameras to watch for movement and sound, recording both when they are detected; these recordings can be saved to the computer, e-mailed or uploaded to the internet. In one well-publicised case,^[3] a computer e-mailed out images as the burglar stole it, allowing the owner to give police a clear picture of the burglar's face even after the computer had been stolen.