A Trigger Relay Module is an electronic switch used to control high-power devices with low-power signals, commonly found in automation, IoT, and microcontroller projects. It isolates circuits for safety and supports various trigger voltages (e.g., 3V, 5V, 12V). Features include optocoupler isolation, normally open/closed (NO/NC) contacts, and LED indicators. Widely used in home automation, motor control, and industrial applications, it ensures reliable switching with minimal interference.