It means nothing. The purpose is to provide a speaker with a moment to think. There are many such words and phrases.

Good is synonymous with mau.Vou give you an example with one sentence: you want my well my bad? You understand what it means?

Oh Thank you so much. It really helped a lot. I think I got it now! Not perfectly but yeah.. I can't seem to use it naturally yet but I think I understand when it's used.. :) I need practice. Thank you. :)

Actually, I'll give a different answer..one you might understand more. You can actually use well in every sentence and it would make sense, it just shows that you're thinking and it's like a filler, like um. In korean, this would be like "geul-sey" It can be used in a bunch of different contexts..for example: "I dislike you.." response: "Well.." In this situation well basically just implies that there is nothing to really say, so in this sense, it does not actually have a meaning, but just implies something. Well can also be used to offer different perspectives or options, like: "Well, if you don't like that then we can do this" In this case, it's offering a different perspective on the situation. But like Randy said, it really doesn't have a meaning..it's kind of meaningless and is just used to give other explanations or imply your thoughts... I feel like i'm rambling and repeating, but I hope this helped. You can message and I can try to give you better explanations!