A webcam is a video camera which feeds its images in real time to a computer or computer network, often via USB, Ethernet or Wi-Fi. Their most popular use is the establishment of video links, permitting computers to act as videophones or videoconference stations. This common use as a video camera for the World Wide Web gave the webcam its name. Other popular uses include security surveillance and computer vision. Webcams are known for their low manufacturing cost and flexibility making them the lowest cost form of video telephony. They have also become a source of security and privacy issues, as some built-in webcams can be remotely activated via spyware.
Computer speakers, or multimedia speakers, are speakers external to a computer that disable the lower fidelity built-in speaker. They often have a low-power internal amplifier. The standard audio connection is a 3.5 mm (approximately 1/8 inch) stereo jack plug often color-coded lime green (following the PC 99 standard) for computer sound cards. A plug and socket for a two-wire (signal and ground) coaxial cable that is widely used to connect analog audio and video components. Also called a "phone connector," rows of RCA sockets are found on the backs of stereo amplifier and numerous A/V products. The prong is 1/8" thick by 5/16" long. A few use an RCA connector for input. There are also USB speakers which are powered from the 5 volt sat 500 milliamps provided by the USB port, allowing about 2.5 watts of output power. Computer speakers range widely in quality and in price. The computer speakers typically packaged with computer systems are small, plastic, and have mediocre sound quality. Some computer speakers have equalization features such as bass and treble controls. The internal amplifiers require an external power source, usually an AC adapter. More sophisticated computer speakers can have a 'subwoofer' unit, to enhance bass output, and these units usually include the power amplifiers both for the bass speaker, and the small 'satellite' speakers. Some computer displays have rather basic speaker’s built-in. Laptops come with integrated speakers. Restricted space available in laptops means these speakers usually produce low-quality sound. For some users, a lead connecting computer sound output to an existing stereo system is practical. This normally yields much better results than small low-cost computer speakers. Computer speakers can also serve as an economy amplifier for MP3 player use for those who wish to not use headphones although some models of computer speakers have headphone jacks of their
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SPEAKER |
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LOW COST SPHERICAL SPEAKER |
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