analog and digital signals there are two different ways of sending information either by analog or by digital signals so what's the difference well let's look at the analog signal on screen we can see that it varies continuously in both amplitude and frequency and the signal can take one of many different values now let's look at a digital signal so here we see that the signal can only take two values either a one or a zero which we sometimes call on or off digital signals are sent as a series of pulses of either ones or zeros
okay so that's great but which is better well digital is a much better way of sending information over long distances now let's see why so here is someone talking on a phone the signal from their voice is analog sound and it enters the phone and is converted to a digital signal and then sent out via microwaves to a phone M which then sends it on to a satellite and then back down to another phone M and then on to the person receiving the phone call let's look at the signal received by that phone if we
look we can see it has picked up a lot of noise or interference but it's still really obvious exactly what it should look like like so the phone can easily convert it back perfectly to be the same as the original signal now let's look at this using analog so now the analog signal the sound enters the phone and is turned into an analog electrical signal and sent down copper wires now note how it picks up noise and interference and the amplitude is reduced as it travels until it gets to the other phone now let's look
at it again it looks very very different to the original signal now it's almost completely impossible to know what this signal should have looked like and it needs amplifying as well this amplification is only going to amplify the noise just as much as it does the signal so noise or interference has really damaged the analog signal and this is why digital is so much better than analog noise or interference is just not a problem for digital but is a huge one for analog making digital signals much higher quality other benefits of digital are that it
can carry much more information in fact you can send multiple different signals all at the same time and digital signals are also easily interpreted by computers
