Plants:

* Photosynthesis: Plants use carbon dioxide, along with water and sunlight, to create their own food (glucose) in a process called photosynthesis. This is the primary way they obtain energy and build their structures.

Animals:

* Cellular Respiration: Animals, like plants, use oxygen to break down glucose (sugar) for energy. This process, called cellular respiration, releases carbon dioxide as a byproduct.

So, while both plants and animals utilize carbon dioxide, they do so in opposite ways:

* Plants: Take in carbon dioxide and release oxygen.

* Animals: Take in oxygen and release carbon dioxide.

This exchange is essential for maintaining the balance of gases in the Earth's atmosphere.