What is the difference between analog and digital representation?

Answer 1

Digital signals are now replacing analog for television transmission worldwide. Digital signals use a stream of digital data (2 differing signal levels to carry binary data) instead of a continuously variable signal level. The biggest difference is that digital data is more resistance to corruption than its analog equivalent. It is this characteristic that means we see a clean signal rather than one with noise in the image as is the case with a poor analog signal.

Digital signals can also be compacted using a technique called data compression. Compression allows signals to take far less bandwidth than they would otherwise need and so more channels can be carried in a given bandwidth. This compression allows HD signals to be broadcast. Broadcasting of HD analog signals would prove challenging.

It is important to understand that digital does in itself not mean higher resolution. Digital SD signals are exactly the same resolution as their analog equivalent. The comparison cannot be made with HD as HD transmission is always digital.

Digital transmission also allows a variety of additional data to be carried within the same signal. Surround sound is one of the more common benefits of auxiliary data.

Answer 2

When we have to declare a magnitude of a measurement, we have to use a numeric value and an appropriate unit. when we take these numeric measurements, we measure it in a way, and represent in another.

As an example, let us consider about the speed and the distance travelled of a motor vehicle. The speed is denoted by the rotation of the speedometer whereas the distance travelled is shown by some numeric value shown in the odometer.

Therefore we can say that there are two ways of representing a measurement.

1. Analog representation

2. digital representation

Analog representation

In analog representation, one measurement is declared by comparing two individual measurements such that the second is directly proportional to the first one. When considered the above example, a device connected to the engine is used to find the speed of the vehicle, and the device is connected to the indicator. Previously, it was said that the speed is measured by the angle the indicator rotated. It means, that the deflection of the indicator is directly proportional to the speed of engine.

Digital representation

In digital representation, the two comparing measurements are not directly proportional, but they show discrete values to certain value. Let us consider a digital watch that shows time by hours and minutes only. After it shows a specific time, say 7.11 pm, after that is shows 7.12 pm. Although the time is continuous, the watch changes its reading once a minute. Therefore we cannot say about the number of seconds passed after the given minutes, and if there was seconds denoted, there would be such problem. Hence, it reveals that the accuracy of a digital device increases when the smallest unit of measurement is decreased (in other words, when the decimal numbers are increased).

Difference

There is an obvious difference between these two representations. Consider two equal tungsten filament bulbs which are controlled by a dimmer-light and a switch respectively. In the first case, the bulb can emit light with different intensities when it is on, but in the next, it has only one intensity available. Most likely, the prior works like an analog system whereas the the latter like a digital system.