Photosynthesis is the process used by plants, algae, and some bacteria to convert light energy from the sun into chemical energy in the form of glucose (a sugar). This chemical energy is then used to fuel the organism's growth and other life processes.

Here's a simplified breakdown of how it works:

1. Light absorption: Chlorophyll, a green pigment found in plants, absorbs light energy, primarily in the red and blue wavelengths.

2. Water splitting: The absorbed light energy is used to split water molecules into oxygen, hydrogen ions, and electrons.

3. Carbon dioxide fixation: The hydrogen ions and electrons are then used to convert carbon dioxide from the atmosphere into glucose.

4. Glucose production: The glucose produced is a form of chemical energy that the organism can use for growth, reproduction, and other metabolic processes.

So, photosynthesis is the key process that allows certain organisms to harness the power of the sun and turn it into a usable form of energy.