The item is a 5V 1-Channel Relay interface board,It can be controlled directly by a wide range of microcontrollers such as, AVR, PIC, ARM and so on.

1-Channel Relay interface board:

Equiped with high-current relay : DC 30V AC250V 30A

Standard interface that can be controlled directly by microcontroller (8051, AVR, PIC, DSP, ARM )

Size:47*36 mm

A single-channel relay module is an electronic switch that lets a low-voltage microcontroller (like an Arduino or ESP32) control high-voltage or high-current devices (like lamps, fans, or motors) by safely isolating the two circuits using an electromechanical relay or optocoupler.

Load Capacity: Up to 10A at 250V AC or 30V DC
Control Voltage (Logic): Typically 3.3V or 5V compatible
Trigger Type: Active-low or active-high (depending on the board design)
Pins: VCC, GND, IN (Control Input)
Output Terminals: COM (Common), NO (Normally Open), NC (Normally Closed)

Home automation projects (switching AC mains lights or appliances)
Controlling DC or AC motors, solenoids, and actuators
Industrial and DIY microcontroller safety isolation