What is an MVP, and why do startups need it?

I’ve been working on a startup idea for a while now, and things have been moving so slowly because I can’t decide on which features to include in my product. A friend mentioned the concept of an MVP (minimum viable product), and it sounded like something I should consider. But I still don’t fully get what it is and how it works. Does this mean I launch something unfinished? Isn’t that risky for a startup? Would love to hear some thoughts or experiences. I don’t want to spend months perfecting everything only to realize I was wrong.