What does a capacitor do in an electronic circuit?

A CAPACITOR STORES electrical energy (charge) in an electric field and releases it when needed. ASVAB Electronics Information tests components. Capacitors store charge on two plates separated by an insulator (dielectric); capacitance is measured in FARADS. Uses: smoothing/filtering power supplies, timing circuits, storing energy, blocking DC while passing AC. Unlike a resistor (which limits current) or battery (chemical storage), a capacitor stores energy electrostatically and can charge/discharge quickly. Knowing the capacitor stores and releases electrical energy is commonly tested.