High-energy physics is a branch of physics that studies the fundamental particles of the universe and the forces that govern their interactions. It often involves experiments conducted in large particle accelerators, such as the Large Hadron Collider, where particles are smashed together at very high speeds to observe the resulting reactions and discover new particles. This field aims to answer fundamental questions about the nature of matter, energy, and the universe itself. Researchers explore concepts like quarks, leptons, and bosons, which are the building blocks of matter, and investigate theories such as quantum mechanics and relativity to understand how these particles behave.