What type of electrical component consists of conductive surfaces separated by an insulator?
Why A capacitor is built from two conductive plates (or foils) separated by an insulating layer called the dielectric. Because no current flows through the dielectric, charge piles up on the plates and energy is stored in the electric field between them. That stored charge per volt is the capacitance, measured in farads.
Watch out A resistor and a potentiometer are both continuous conductive paths that oppose current and turn energy into heat; an oscillator is a whole circuit that generates a signal, not a two-terminal component.
Two plates plus an insulator between them = capacitor. Conductor, insulator, conductor is the capacitor sandwich.