Analog recording (Greek, ana is "according to" and logos "relationship," "word") is a technique used for the recording of analog signals which, among many possibilities, allows analog audio and analog video for later playback.
Analog audio recording began with mechanical systems such as the phonautograph and phonograph. Later, electronic techniques such as wire recording and tape recorder were developed.
Analog recording methods store signals as a continuous signal in or on the media. The signal may be stored as a physical texture on a phonograph record, or a fluctuation in the field strength of a magnetic recording. This is different from digital recording where digital signals are quantized and represented as discrete numbers.
Modern tape recorder
The introduction of tape bias to recording systems improved fidelity to acceptable and eventually high-fidelity performance. Adding a DC bias to the signal sent to the recording head reduced distortion in the recording. The use of an AC bias further reduced distortion and greatly improved the frequency response of recording systems.