Maybe this is a stupid question, but what exactly is sexual harassment? I guess I'm confused. If a co-worker asks you sexually oriented questions, does that count?

My story: About a month ago, there was a co-worker that I worked with who made me feel uncomfortable. He was about 45 years old, and I'm 21. At first, he only complimented me on my looks and said things like "I really enjoy working with you", "you're a very sweet girl", etc. Then one day on break, he sat down with me. He asked me if I was a virgin, and asked if I'd ever have sex before. He said, "What you tell me will be kept secret." I wasn't sure how to respond, so I answered with "Are you kidding?" Later on, he just told me to think about it, and asked me to marry him. I think the marriage idea was a joke, because he has a wife with a daughter. Anyway, he found my number through our supervisor. I don't think he had permission to find it to call me, but he did. He called my house and asked me to meet him. On off days, I was told my employees that he came in looking for me. Thinking that a good talk would end this, I agreed to meet him. He came in, and kept suggesting that we get together. I'm pretty sure he was only interested in sex. he told me about his past history with hookers, and that he would never do that again because if he had someone like me, he'd treat her right. I ended up quiting work, because I felt very uncomfortable.

I didn't have a salary for about a month, and did something I shouldn't have done which is another story.

I guess what I want to know is what counts as sexual harassment. He never touched me, but he made sexually-directed statements. I'm not looking to press charges because this man has a family, but I would like to know in case something like this happens in the future.