A resonant circuit, also known as a tuned circuit, is an electrical circuit that can oscillate at a specific frequency. It typically consists of an inductor (L) and a capacitor (C) connected together. When energy is supplied to the circuit, it can store energy in the magnetic field of the inductor and the electric field of the capacitor, allowing it to resonate at its natural frequency. Resonant circuits are widely used in various applications, including radio transmitters and receivers, where they help select specific frequencies for communication. By adjusting the values of the inductor and capacitor, the resonant frequency can be tuned to match the desired signal, enabling efficient transmission and reception of information.