0 and 1 are human definitions like time and date. You can define any state to be a 0 and any other to be 1, whether it is flowing electrons, flowing water, on-o

0 and 1 are human definitions like time and date. You can define any state to be a 0 and any other to be 1, whether it is flowing electrons, flowing water, on-off light, etc. By doing this you gain a simpler model on which you can reason. You can even expand it to whether a 'neuron' is firing (1) or not (0). What causes the firing does not matter, may it be digital or analog, discrete or continuous. You want to represent more than two states? Use multiple 1s or 0s, and you can still use the model. Use something else? Now you have to create your own model where you can map your states and state changes, along with all mathematics associated. You can no longer compare a USB 'byte' with this new model 'byte'. What even is a 'byte' in your new model? It's like comparing apples and oranges. It usually all depends on how accurately you can measure your states, often limited by the signal-to-noise ratio. When is a 0 really a 0 (signal) and not a 1 (noise). A good example is telecommunications, where the data is sent over an electromagnetic wave (analog, continuous). In the past you could only identify between 32 states, but now due to better sensors you can identify 2048 states, increasing your data density by 64x. Same goes for HDD and SD card storage.