Sunlight & Shade

Full Sun: At least 6 full hours of direct sunlight.
Many sun lovers enjoy more than 6 hours per day, but need regular water to endure the heat.

Partial Sun / Partial Shade: These two terms are often used interchangeably to mean 3 – 6 hours of sun each day, preferably in the morning and early afternoon.

              • However if a plant is listed as Partial Sun, greater emphasis is put on its receiving the minimal sun requirements.
              • If a plant is listed as Partial Shade, the plant will need some relief from the intense late afternoon sun, either from shade  provided by a nearby tree or planting it on the east side of a building.

Full Shade: Less than 3 hours of direct sunlight each day, with filtered sunlight during the rest of the day.
Full shade does not mean no sun. There aren’t many plants
other than mushrooms that can survive in the dark!

If you need more detail on this subject, please refer to the following article:
A gardener’s guide to sun exposure by Southern Living Plants.