What is the differnece between a analogue and digital signal need a detailed answer?

Question

What is the differnece between a analogue and digital signal need a detailed answer?

Answer 1

The video signal of analog television is transmitted in AM, while the audio is transmitted in FM. Analog TV is subject to interference, such as ghosting and snow, depending on the distance and geographical location of the TV receiving the signal. The amount of bandwidth assigned to an analog TV channel restricts the resolution and overall quality of the image. The current analog TV signal standard (in the U.S.) is referred to as NTSC.

Digital TV, is transmitted as data bits of information, just as computer data is written or the way music is written on a CD. In this way, the signal is basically "on" or "off". In other words, the intent of DTV technology is that the viewer either sees an image or nothing at all. There is no gradual signal loss as distance from the transmitter increases. If the viewer is too far from the transmitter or is in an undesirable location, there is nothing to see. Since the DTV signal is made up of "bits", the same bandwidth size that takes up a current analog TV signal, can accommodate not only a higher quality image in digital form, but the extra space not used for the TV signal can be used for additional video, audio, and text signals.

In other words, broadcasters can supply more features, such as surround sound, multiple language audio, text services, and more in the same space now occupied by a standard analog TV signal. However, there is one more advantage to the ability of a Digital TV channel's space; the ability to transmit a High Definition (HDTV) signal.

Lastly, another difference between Digital TV and Analog TV is the ability to broadcast programming in a true widescreen (16x9) format. The shape of the picture more closely resembles the shape of a movie screen, which enables the viewer to see the movie as the filmmaker intended. In Sports, you can get more of the action in one camera shot, such as viewing the entire length of a football field without making look like it is a long distance away from the camera.

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Answer 2

A digital signal is just a special case of analog.

Analog has voltage swings at different voltages in a sine wave.  The voltage difference means ... louder or softer.

The cable, the electronics, noise during the transmission all affect the analog signal.

A digital signal is ENCODED by saying:

Anything between 0 and .8 volts is a zero

Anything above .8 volts is a one

And both sides agree how fast/times per second the data will flow.

Suddenly - small noises, changes because of the cable, etc no longer matter.  You could suffer 50% signal reduction, but the destination still gets perfect data.

So its the encoding the ones and zeros to transfer a signal that is the magic.  Both sides have to agree on the encoding.