Thailand has a huge transgender population so you will hear the word "ladyboy" or "Kathoey" in Thai a lot. Even though, you will hear jokes about ladyboys, be respectful as they are a well known recognized subgroup that contributes to the Thai culture.
What is a ladyboy?
A Ladyboy is a transvestite known as "Katoey." Although you can tell some apart, for the most part, you can't. They are gorgeous and super duper feminine. They are highly accepted and well integrated into the Thai society whether that's from working in the beauty industry, the entertainment industry, in airlines or prostitution. Some of them have gone as far as having breast implants, face construction, and more which makes it hard to tell them apart. However, the ones you will be able to tell apart, are the ones that still have male features. They usually work in tourist places.
Economic Ties
In a way, economy plays a role. In the jobs I've mentioned in the previous paragraph, a female can often earn more than a male can. And because of that, many Ladyboys prostitutes have gotten major work done to themselves, and since many western men cant tell apart a Thai woman from a Ladyboy, they can easily make money for the week in one night.
Religious & Cultural Acceptance
Some Ladyboys open up about their sexuality at a young age, and their parents are very accepting and don’t force them to hide.
They have no conflict with their faith since Buddhism as the main religion of Thailand plays a part in this acceptance. Buddhist monks also support same-sex marriage in Thailand making it easy to be accepted as Ladyboys.
Homosexuality isn't a modern phenomenon in Thailand since it goes way back to centuries. Though they are widely accepted, in some parts of Thailand, they aren't very fond nor accepting towards Ladyboys.
Majority of Ladyboys work in the bigger cities and tourist spots, and that's where you will see them the most or at all. I don't believe you will see them as much once you leave the touristy spots. As I mentioned before, please be respectful toward Ladyboys you may encounter. Not only because they are part of a recognized subgroup, but because they aren't any different from the rest of us.