Textbook in PDF format This book introduces essential concepts in relativistic kinematics for high-energy nuclear and particle physics, with a focus on quark-gluon plasma physics, after covering all the needful basics of the special theory of relativity. It explores multiparticle production processes in ultra-relativistic hadronic and nuclear collisions. While a foundation in nuclear and particle physics and the special theory of relativity is recommended, the book also includes key concepts of relativity to support understanding in later chapters. With numerous real-world examples and solved problems, this book equips master’s and graduate students, as well as early-career researchers, with the mathematical tools and practical techniques needed to navigate the kinematics of hadronic and heavy-ion physics efficiently. It also covers the relevant observables used in quark-gluon plasma physics analysis