This lecture covers the performance and operational limits of tokamaks in the context of plasma physics and fusion energy. It discusses critical parameters for a fusion reactor, such as plasma current, density, and pressure limits, as well as disruptions and operational constraints. The presentation includes a review of fusion performance factors, the importance of energy confinement time, and the impact of plasma current and density on fusion reactivity. Operational limits related to global MHD instabilities, Greenwald density limit, and plasma pressure are explored. The lecture also addresses disruptions, ideal MHD instabilities, and disruption mitigation techniques. Overall, it emphasizes the significance of optimizing parameters within operational ranges to avoid disruptions and degradation in confinement.