The term "photoelectric" refers to the phenomenon where light or electromagnetic radiation causes the emission of electrons from a material. This effect is commonly observed in certain metals, where photons from light can provide enough energy to dislodge electrons, creating an electric current. The photoelectric effect is a fundamental principle in physics and is crucial for the operation of devices like solar panels and photoelectric sensors. It was first explained by Albert Einstein in 1905, which helped establish the concept of light behaving as both a wave and a particle.