Answer:
We know that a solar electrical panel converts sunlight to electricity by means of solar cells and then, the electricity can be used as any electrical current.
I am not familiar with solar heating panels but assume that a liquid is heated by sunlight and then circulated thru the area that needs heating - it converts heat from sunlight to usable heat. The heat energy could also be stored and delivered at a different time (accumulated during the day and delivered at night). This is somewhat similar to a company freezing water at night when electricity is cheaper and then using the cooled water during the day for cooling.