So I've been reading a book about electrical engineering and I still don't understand this: In a series circuit, the current stays the same, right? But when there is a resistor, it resists the current and less current goes into an LED and it shines less brighter. How is that possible. The resistor resists current right? Then anything after the resistor will experience less current, then the current is not the same throught the circuit? Sorry, I still don't quite understand how voltage works and I guess somehow the resistor resists voltage? Please, help and sorry, i've read many articles and a few books but nothing helps. If you could please explain in the easiest way possible how current and specially voltage works. Thanks!
In this case it helps if you think of electricity as a chain drive rather than as a flow of electrons.
If you have a chain driven by a crank like a bicycle, and the chain goes around multiple pulleys each with it's own "resistance" you can see that for any given force (voltage) applied to the crank, or more accurately, energy, the chain will move at a speed dictated by the total amount of "resistance" in the "circuit" of the chain.
If you add more pulleys. with more resistance, for the same energy applied the chain speed (current) is smaller.
Electricity works almost exactly like that. The current in a simple loop circuit is the same everywhere in the loop, just like the mechanical chain. The force/energy driving all that is the voltage at the battery or power supply.