: CTs (Current Transformers) and VTs (Voltage Transformers) step down high values to safe levels for relays.

The primary purpose of an strategy is to identify and isolate faults as quickly as possible to ensure personnel safety, prevent equipment damage, and maintain grid reliability. Because distribution networks are often radial and exposed to the elements, they are highly susceptible to transient and permanent faults. 1. Fundamentals of Distribution Protection

Modern IEDs communicate via IEC 61850 (GOOSE messages). This allows high-speed peer-to-peer tripping without traditional copper wiring.