What does "soul mate" mean?

Native speaker’s answer
Rebecca
Some people believe in the concept of soul mates, which is that there is a person out there that is perfect for you, that is made for you. That person is supposed to be the perfect romantic partner for you. Of course, it's just a theory and many people do not believe in it. Ex: I met my soul mate in high school, and now we have been together for 30 years. Ex: I can't believe you're getting married. Is your fiancé your soul mate?