Final answer:
Photosynthesis is the process where plants convert sunlight, carbon dioxide, and water into glucose for their own energy needs.
Step-by-step explanation:
The process by which plants make their own energy is called photosynthesis. This is a crucial biological function where plants use sunlight, carbon dioxide, and water to produce glucose, a form of sugar that serves as their food, and oxygen. During photosynthesis, energy from the sun is converted into chemical energy in the form of glucose, an organic compound, which is a significant process for both plants and other organisms that rely on plants for food.