1. Full of or characterized by animation, vigor, or courage: a spirited debate. 2. Having a specified mood or nature. Used in combination: high-spirited; low-spirited.
One product of photosynthesis is glucose (sugar), which provides the basis for most food chains. The second product of photosynthesis is oxygen which comes in handy if your happen to be an aerobic organism that requires oxygen for survival.
Photosynthesis is the process in which plants (also autotrphoic protists and some bacteria) use light energy, from the Sun, to make sugars and organic food molecules from CO2 and water (H2O). This process is essential for the formation of not only energy, but also for the formation of glucose for purposes of structure.