Full Sun Conditions
When you let the sun shine in!
Heliophilous is the term that describes these plants: helio for "sun," and philous for "to like." Direct, warm, long-lasting sunlight is what this means to a plant.
A south-facing window or balcony will receive the most sun (in the northern hemisphere, that is), assuming that the light is not blocked by other buildings or trees.
A lot of desert plants and cacti fall into the full sun category. Other plants that do especially well in full sun are flowers and most vegetables.
While it is possible to keep full sun plants alive in areas that get less than six hours of direct light a day, the results aren't as good. Plants need all the energy they can get to produce flowers, fruits, and vegetables.