Explore relativistic hydrodynamics in this comprehensive lecture by Sadhana Dash, part of the International School and Workshop on Probing Hadron Structure at the Electron-Ion Collider. Delve into the fundamental concepts and applications of relativistic fluid dynamics, essential for understanding high-energy nuclear collisions and the quark-gluon plasma. Learn how this theoretical framework contributes to the study of matter under extreme conditions and its relevance to the upcoming Electron-Ion Collider experiments. Gain insights into the mathematical formalism and physical principles that govern the behavior of relativistic fluids, preparing you for advanced research in nuclear and particle physics.