Full Sun - 6 or more hours with most of it between 11 & 4.
Part Sun -Sun from 11/Noon to 4.
Part Shade - Sun from sunrise to 11/Noon
Shade - filtered, dappled or partial shade from sunrise to 4. More light than dense shade. Like outer areas of a trees dripline.
Dense Shade - No rays or beams filtering into the area at any point of the day.
When a plant needs 6 or 8 hours of sun that means full sun, most of it direct and in the afternoon from noon on.
With your part shade site that's good for plants that can tolerate some sun but need shade from direct afternoon sun. Geraniums and impatients do well in a site like this. You want to count sun hours as direct sun. This site would not be enough direct hours of sun for roses