Why does it rain during the sunny day? What are factors that cause rainfall while the sun is still shining. The phenomena is known as sunshower?

The information I found so far is very limited. Please help me answer this question if you know anything about it.
I think Wikipedia explains quite well. It is the wind that transport the airborne water droplets from a nearby showering cloud. It is quite common in UK especially near the coast which is often very windy. Usually the weather forecast will say that it has scattered shower with sunny spell.
https://en.wikipedia.org/wiki/Sunshower