Audio recording is a re-creation of sound waves like spoken voice, singing, music or sound effects. There are 2 basic categories of audio recording. There is analog recording and digital recording. Analog recording is created by using a small microphone that can detect changes in sound waves and record them as a representation of the sound waves onto a medium or in magnetic tape recording. Then it would convert this into electric current, which then creates a representation of the sound as a magnetized area on a plastic tape.
Digital recordings take the analog signal and convert it into binary numbers. Digital recordings are considered higher quality than analog recordings because this format can prevent quite a bit of loss of quality that is commonly found in analog recordings. This loss is due to noise in the playback as well as mechanical deterioration or damage to the storage medium. A digital audio signal must be reconverted to analog form during playback before it is applied to a loudspeaker or earphones.
Electronically generated sounds may also be recorded directly from devices such as an electric guitar pickup or a synthesizer or directly from a microphone.
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How to Record Audio and Music on a Computer
http://www.intel.com/content/www/us/en/tech-tips-and-tricks/how-to-record-audio-and-music-on-a-computer.html