What does Ethical Non Monogamy mean?

I’ve been single for a while and finally decided to start dating. I’m talking to a few people and it’s been fun getting to know them and going on a few dates with them. None of them have asked to be exclusive, we’re all looking for something casual and not serious. Am I in an ENM? If not, what entails that I would be? I have been intimate with one of the persons I’m talking to but I haven’t with anyone else. Just want to make sure I’m being respectful to everyone but also ensuring I’m okay to just be single and date people? Sorry if this was confusing to read. I’m honestly confused myself.