[capn_duck]

Bias is how all electric components work. All they know about is the difference in voltage between their electrodes, not any absolute voltage w.r.t the rest of the circuit.

[itishappy]

Voltages lack the concept of zero, so we need a comparison to be able to do certain math (like addition) nicely. Here's an article explaining why!

https://math.ucr.edu/home/baez/torsors.html

Here's the post I pulled it from!

https://news.ycombinator.com/item?id=33678771