Hi Fatima!
I think that the comments that you made pertaining to your research on Google are accurate for the most part.
If it's an inquiry about rain in general, "I like rain, do you like rain?" When you think about rain as a concept, something that happens, "do you like rain?"
When you use a definite article "the rain" as in "I like the rain, do you like the rain?" It refers to the rain that is occurring in the here-and-now or the rain that you can see now.
It reminds me of another example that might occur in a restaurant. "Do you like wine?" "Do you like the wine?" So, do you like "wine" in general as a drink?" "Do you like "the wine" that was served and that you are drinking now?"