The article provides an overview of protective relaying principles and their applications for high-voltage power system components. It covers the protection methods for generators, transformers, buses, and transmission lines using various relay types to detect and isolate faults. IEEE/IAS/I&CPSD Protection & Coordination WG Chair Jacobs Canada, Calgary, AB rasheek. As transmission systems grow increasingly complex with integration of renewables and smart technologies, the design, configuration, and application of protective relays have become more. Selectivity is a mandatory requirement for all protection, but the importance of it depends on the application. Ensure fast, selective fault clearance per IEC/IEEE standards.