Explore the fascinating world of active matter and self-organization in this comprehensive lecture from the International Centre for Theoretical Sciences. Delve into non-equilibrium physics, examining run-and-tumble bacteria, self-propelled colloids, and motility control as a self-organization principle. Investigate position-dependent self-propulsion, quorum-sensing interactions, and light-controlled active colloids. Analyze the hydrodynamics of equilibrium phase separation and quorum-sensing active particles through exactly solvable cases. Discover motility-induced pattern formation in bacterial colonies, including multi-component systems, and learn about experimental results and macroscopic dynamics. Gain insights into the origin of patterns, overall dynamics, and N-species motility-induced pattern formation in this in-depth exploration of active matter physics.