To be digital means that there is a finite number of possibilities, rather than an infinite amount.
The English alphabet is a good example because there are only 26 letters. Imagine you are reading a note with messy or smudged handwriting. You would still be able to figure out what it says. Why? Because you already know the alphabet, and have a limited set of letters that makes it possible to decipher the letters or words even if they’re distorted. The smudges or messy handwriting in this example is the noise, which distorts the letters (the signal). Since the set of possible letters is limited, your brain can use the process of elimination to recover the intended message.
That is the essence of digital.
Anything sent over the internet must be encoded in 0s and 1s. It is the easiest and most reliable way to represent digital information. You may be wondering why 0s and 1s, and the answer is fairly simple. It’s all about the noise. In the digital world, 0s and 1s can get really distorted from the noise but still maintain their meaning.
When a computer really can’t tell if it’s receiving a 0 or a 1, it may freeze, ask for a re-transmit, or blank and move on. This is because digital systems are designed to either get things right or try again.