photovoltaic cell is a solid-state electronic device that takes in light energy and converts it directly into electrical energy. this is sort of like a light bulb that is acting in reverse.
the typical blue/silver solar cell has a base of the element silicon. The silicon is doctored so that some loosely held electrons in the silicon cold be bounced into the electrical circuit.
These moving electrons, also known as electrical current,can power electronic devices, especially devices that have low power reguirements.
Low power devices would be things like calculators, radios, LED lights, electronic switches, monitoring equipment, rechargers for batteries, and such.
Solar cells have made space habitation and space research possible.