Stellar nucleosynthesis is the process by which stars create new elements through nuclear fusion. In the cores of stars, extreme temperatures and pressures allow hydrogen atoms to fuse into helium, releasing energy. This process continues in more massive stars, where heavier elements like carbon, oxygen, and iron are formed through successive fusion reactions. When a star exhausts its nuclear fuel, it may explode in a supernova, dispersing these newly formed elements into space. This enriches the surrounding interstellar medium, contributing to the formation of new stars, planets, and even life, as elements like carbon and oxygen are essential for organic compounds.