The phenomenon that describes the emission of electrons from a metal surface when light shines on it is the Photoelectric effect.
Step-by-step explanation:
The term photo is used to define light and so photoelectric effect defines the phenomena when the light falls on the metal and the resultant effect of electrons on the surface of the conductor. Photoelectric effect also known as photoemission.
When the light is made to be incident on the surface of a conductor, electrons are discharged or released from the metal. Here the energy of the light acts as a work function so that it is used for the energy that is required to emit electrons.