Question

name the resistors do not answer anything

Answer 1

resistors circuit-design resistance short-circuit
I have always had a basic understanding of electronics. I am now starting to learn a bit more, using an Arduino as a test platform, and I have a question about resistors that I can not seem to solve through research.

Why do we use them? I understand that they limit current. (In the case of an LED, too much current would heat it up and burn it.) But how is this measured/calculated/chosen? I am not specifically asking about an LED use case, or how to use an LED. I am trying to understand "why" resistors are needed on a physics level.

What happens to the rest of the current not used (because of the resistor)?
Does the LED then use ALL of the current available in the circuit? If not, where does the rest go? (Recycled back into power source?)
Why does an LED "drop voltage" by a certain amount? And what happens to the rest of the components in series, does the voltage drop for every component, up until there is nothing left? This would make sense, but an LED does not have internal resistance (so it is explained), so why does it drop voltage?
I recently watched a video, where the guy explaining resistors, drew a sketch showing 12 V → resistor → LED --- 0 V (Do you choose your resistor to the extent of "using up all the current/voltage" before it gets to the end of the circuit? YouTube video
Why does a battery go into a dead short if you connect the terminals directly, but if you add a light bulb (resistor), it does not?
I have done hours and hours of research, and I understand what a resistor does, but I do not understand why it is needed (to not dead short a battery? ... Does this mean it "eats" all of the power before it returns to the anode?)
Why do different light bulbs work on the same battery (different resistance, but no dead short?)
I know these questions are broad, and I am not specifically looking for answers to each of them individually. I am mentioning these multiple questions above to demonstrate that I do not have a firm grasp on the concept of why a circuit needs resistance. This would be the question to answer.