Here's a breakdown:

* Photosynthesis: The process where plants use sunlight, water, and carbon dioxide to create their own food (glucose) and release oxygen.

* Sunlight: Provides the energy that drives the chemical reactions within photosynthesis. It's absorbed by chlorophyll, a green pigment found in plant cells.

* Chlorophyll: Acts like a solar panel, capturing light energy and converting it into chemical energy.

So, in short, the sun is the ultimate source of energy for plants during photosynthesis.