Solar Panels
Solar panels are devices that convert light into electricity. They are called "solar" panels because most of the time, the most powerful source of light available is the Sun, called Sol by astronomers. Some scientists call them photovoltaics which means, basically, "light-electricity."
Mono Panels
Each cell is a slice of a single crystal of silicon that is grown expressly for the purpose of creating solar panels.
Poly Panels
Each PV cell is made of multiple silicon crystal fragments that are melded together during manufacturing. You may see them called “multi-crystalline panels” or “poly panels.”