You're describing the process of photosynthesis, a fundamental process in plant life and some bacteria that uses sunlight, water (H2O), and carbon dioxide (CO2) to produce energy in the form of sugars (glucose) and releases oxygen (O2) as a byproduct.

Here's a simplified breakdown:

1. Light Absorption: Plants and some bacteria contain a pigment called chlorophyll, which absorbs light energy, primarily from the red and blue portions of the visible spectrum.

2. Water Splitting: The absorbed light energy is used to split water molecules (H2O) into hydrogen ions (H+) and oxygen (O2). The oxygen is released into the atmosphere as a waste product.

3. Carbon Dioxide Fixation: The hydrogen ions are then used to reduce carbon dioxide (CO2) from the air into sugars (glucose), which provide the plant with energy for growth and other processes.

The Overall Equation for Photosynthesis:

```

6CO2 + 6H2O + sunlight → C6H12O6 + 6O2

```

Key Points:

* Sunlight: Provides the energy for the chemical reactions.

* Water (H2O): The source of electrons and hydrogen ions needed for the reactions.

* Oxygen (O2): A byproduct of water splitting.

* Glucose (C6H12O6): The main product of photosynthesis, providing energy for the plant.

In essence, photosynthesis is a process where light energy is converted into chemical energy in the form of sugars, with oxygen being a waste product of the process.