What type of electrical component stores energy in a magnetic field?

An inductor stores energy in a magnetic field that is generated whenever electrical current flows through it. When the current increases, energy is stored in the expanding magnetic field, and when the current decreases, the magnetic field collapses, releasing that energy back into the circuit to oppose the change in current. This question is the direct counterpart to the capacitor question. The key distinction to memorize is that inductors rely on electromagnetism (magnetic fields) while capacitors rely on electrostatic charge (electric fields). Diodes and varistors are completely unrelated to energy storage.