Gotta agree with @the_grinch. The difference between flirting and harassment is wether it is welcome or not, and wether or not you stop if given signals or told. Some people are more likely to be more welcoming to advances from a person with looks or money. Those two things generally don’t hurt your odds- but some people could give a crap. They may not be impressed by your looks or after cash, and they may just not be interested at all in anyone. And yeah- some people are ONLY after looks and or money so they don’t care. That’s their prerogative. You don’t have to like it, agree with it, or understand it. We just gotta respect that each of us is a human being with our own wants and desires and respect the other person.
Harassment is when you are asked to stop and don't. Assault is when you touch someone who has asked you not to, and still keep doing it. If you cannot tell the difference between these and flirting, YOU have a serious problem. In fact you likely ARE part of the problem.
If someone says "I dont like you doing/saying that to me" and you keep doing it anyway, that's harassment