I want to know what are the advantages of the module designed by sunrom technologies to control the intensity of a bulb other than a relay or transistor to do the same work.
I do not know module parameters but I can assume it i an electronic light dimmer. You can dim a light from a bulb with a series resistor but then you lose a lot of power by dissipating it as heat from that resistor. Instead, electronic light dimmers interrupt the current by pulses, and the current in the bulb is varied by pulse length or frequency depending on dimmer design.
For the cost of such dimmer you save on the heat otherwise lost in the resistor
As I can see now, it is an AC triac dimmer with a digital control. In the data sheet it is shown that using two push-buttons you can adjust light intensity or a fan speed in 16 steps from zero to full output.
You could make a similar dimmer for DC circuits using a transistor but like with resistors, there will be a heat dissipation which wastes energy. In AC circuits the described dimmer does not dissipate power by sending longer or shorter AC pulses to load ac described. Only please make sure the load is "resistive" like lamps or small fans. Inductive or interrupted loads like power motors or drills can kill the Triac in the dimmer.