What is Analog ?

 A method of transmitting information using energy waves. It doesn't have discrete levels but is a continuously variable wave. Human voice for example is transferred by directly converting the sound wave to electricity.

Analog cell phones (known also as 1G) used this technology. However virtually all modern cell phones use digital signals (2G or later).

Analog is an adjective that describes a continuous measurement or transmission of a signal. It is often contrasted with digital, which is how computers store and process data using ones and zeros.

While computers are digital devices, human beings are analog. Everything we perceive, such as what we see and hear, is a continuous transmission of information to our senses. This continuous stream of input is not estimated, but received and processed by our brains as analog data.

Analog signal:-

At its base, an analog signal is a continuous signal in which one time-varying quantity (such as voltage, pressure, etc.) represents another time-based variable. In other words, one variable is an analog of the other. The result is that analog systems allow for a theoretically infinite number of values to be represented: it can achieve any value within the parameters governing the system.

As an example, imagine a dimmer switch tied to a light bulb. In a perfect analog system, the dimmer will have an infinite number of positions between “off” and “full” – and a correspondingly infinite number of levels of output by the lightbulb. The output by the bulb is analogous to the time-dependent variable “position of the dimmer switch.”

Examples of Analog Signals

In theory, we can use the term “analog signal” to describe any continuous signal that uses one time-variable quantity to represent another (such as mechanical systems like a dial thermometer). But for our purposes, we use it most commonly to describe electrical signals.

We use analog signals in a wide variety of applications, such as:

- Audio recording and reproduction

- Live sound/amplification devices

- Older video signal transmission technologies (VGA, S-Video, etc.)

- Radio signals

- Television broadcast signals (until recently)