A particle collider is a type of scientific instrument used in particle physics to accelerate particles to very high speeds and smash them together, allowing scientists to study the fundamental particles and forces that make up the universe. Particle colliders are used to investigate the properties of particles such as electrons, protons, and neutrons, and to search for new particles that have not yet been discovered. By studying the collisions that occur in a particle collider, scientists can gain insight into the fundamental laws of physics and the structure of the universe. Particle colliders are typically large and complex machines that require sophisticated technology to operate. Some of the most famous particle colliders include the Large Hadron Collider (LHC) at CERN in Switzerland and the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in the United States.