A webcam is a small camera attached to a computer. They serve a variety of purposes, from taking still images to sending a live video over conference calls. Many laptops have a webcam built in to the computer screen, but external webcams are also sold. If you purchase an external webcam for use, you may also need to get a microphone if you plan on using the camera for either captured or live video.
A webcam can function as a digital camera, snapping still images. In most cases, once a webcam is activated, and the image it is pointed at appears on your computer screen, a picture is taken by hitting a specific key on the keyboard or clicking a button on the screen. Once an images is captured, it is saved to the computer hard drive.
Webcams can also record short video messages. Similar to taking still images, videos are captured by clicking on a designated button on the computer screen. Unlike still images, videos require the act of starting and then stopping the camera. The start and stop button are usually the same, and have a red blinking circle when the camera is recording. A video is saved to the computer's hard drive.
Many Internet programs, such as Skype, offer video conferencing. During video conferencing, a webcam allows a user to offer a video image of himself as he talks with another person online. Video conferences are not usually recorded, but rather display a live feed of whatever the webcam is currently capturing. If one user has a webcam and the other doesn't, the user without a webcam can only send out audio during the call, even though he can see the video from his contact.
Some websites allow users to upload photographs. If you have a webcam, you can often take a photograph with the camera and post it online without having to navigate away from the website itself. For instance, Facebook users can select "Use Webcam" to take a picture with their webcams and post it to their profiles without ever leaving Facebook. Likewise, many websites offer users the ability to record and upload webcam videos from within the site.