C3 plants are a type of plant that use a specific process called photosynthesis to convert sunlight into energy. In this process, they absorb carbon dioxide from the air and combine it with a five-carbon sugar to produce a three-carbon compound. This is why they are called "C3" plants, as the first stable product of photosynthesis is a three-carbon molecule. These plants thrive in moderate climates and include many common species, such as wheat, rice, and soybeans. C3 plants are most efficient in cool, moist environments but can struggle in hot, dry conditions, where other types of plants, like C4 plants, may perform better.