Panels work in different ways depending on what they are used for. if you have a solar water heating system, this usually contains a “collector” to absorb solar radiation and turn it into heat. Then, a heat conducting liquid carries the heat from the collector to the hot water tank.
An electricity producing system, a positively charged layer of silicon is placed against a negatively charged layer of silicon, forming a field for electrical charges to pass through. Sunlight creates the electric charge when it shines on the panel. Then a conductive metal concentrates the charge into an electric current which can power household appliances.