This document discusses antimatter, including its definition as matter composed of antiparticles with opposite charge from normal matter. Antimatter annihilates with normal matter in a burst of energy. It was first theorized in 1928 and the antiproton was discovered in 1955. Antimatter is produced in high-energy particle collisions and can be artificially made using particle accelerators like CERN's Large Hadron Collider. It is extremely difficult and expensive to produce and store antimatter due to its tendency to annihilate. Potential applications of antimatter include medical treatments, fuels for advanced propulsion in space travel, and weapons if ever produced in large enough quantities.