A representation of an object that resembles the original. Analog devices monitor conditions, such as movement, temperature and sound, and convert them into "analogous" electronic or mechanical patterns. For example, an analog watch represents the planet's rotation with the rotating hands on the watch face. Analog telephones turn voice vibrations into electrical vibrations of the same shape. Analog implies a continuous signal in contrast with digital, which breaks everything into numbers. Analog video cameras scan their viewing area a line at a time and convert the infinitely varying intensities of red, green and blue (RGB) light into analogous electrical signals. See sampling
Analog Is Alive and Well
Audio and video have been analog since the beginning of radio, TV and magnetic recording. While the industry is almost entirely digital today, analog exists in the form of AM/FM radio, and vinyl records are still being pressed, although nowhere near the volume in their heyday. Many home recordings on audio cassettes and VHS tapes are still around as well.
The ability to capture the infinite nature of the real world is the advantage of analog audio recording, which is why vinyl records have not disappeared. It takes huge digital capacities and bandwidth to match that same granularity. See vinyl record
and high-resolution audio
The downside of analog is that once recorded, analog equipment cannot copy signals perfectly, no matter how advanced. Third and fourth generations of analog audio and video recordings show noticeable deterioration.
In contrast, by recording in digital from the beginning, or by converting from analog to digital at an early stage, audio and video data can be preserved indefinitely and copied over and over without deterioration. This fact caused music and movie publishers great anguish and has always been a problem for software publishers. See copyright
, peer-to-peer network
and A/D converter
There are many analog systems in the world such as analog telephones that turn sound waves into electrical waves.
In AM/FM radio, the original sound waves are maintained as analogous electrical waves throughout the entire chain from recording microphone to the listener's speakers. The analog waves are transmitted over the air within the radio station's carrier frequency.