Young web camera
Various lenses are available, the most common in consumer-grade webcams being a plastic lens that can be manually moved in and out to focus the camera.
Fixed-focus lenses, which have no provision for adjustment, are also available.
Digital video streams are represented by huge amounts of data, burdening its transmission (from the image sensor, where the data is continuously created) and storage alike.
Webcams have become a source of security and privacy issues, as some built-in webcams can be remotely activated by spyware.
To address this concern, many webcams come with a physical lens cover.
The most popular use of webcams is the establishment of video links, permitting computers to act as videophones or videoconference stations.
Typical interfaces used by articles marketed as a "webcam" are USB, Ethernet and IEEE 802.11 (denominated as IP camera). Various proprietary as well as free and open-source software is available to handle the UVC stream.
One could use Guvcview or GStreamer and GStreamer-based software to handle the UVC stream.