Antimatter refers to hypothetical matter consisting of antiparticles, which possess the same mass as conventional particles but carry opposite electrical charges. When an antiparticle interacts with a particle, they undergo a process called annihilation, wherein their combined mass is converted entirely into energy, most often in the form of high-energy gamma radiation. Because of this highly reactive nature, antimatter must be stored and contained using intense electromagnetic fields to prevent accidental contact with normal matter. The theoretical study of antimatter is crucial in particle physics, as it helps researchers test fundamental symmetries, such as CP symmetry, and better understand the laws of physics governing particle interactions throughout the cosmos.