Full Sun: Is six or more hours of direct sunlight per day. This doesn’t have to be continuous; you could have four hours in the morning, shade mid day, and four hours in the afternoon. As long as it is direct full, sun.
Part Sun: Plants thrive with between 3 and 6 hours of direct sun per day.
Part Shade: Plants require between 3-6 hours of sun per day, but need protection from intense mid-day sun.