Help me understand inductors
Here are some definitions of inductor:
"An inductor is a passive electrical device that stores energy in a magnetic field, typically by combining the effects of many loops of electric current."
"A coil onto which voltage is imposed by another coil."
After reading so many definitions I still don't understand why we use an inductor. I look at my old motherboard and see coils (inductors). If I was making a motherboard, why would I use a coil? To clear out bad frequencies? Why wouldn't I use a capacitor instead?