Love is a human patent, and it generally refers to the relationship between a man and a woman before it can be called love. People have thoughts, thoughts, and emotions. People often say that love develops over time or love at first sight. Generally speaking, it means that a man and a woman develop a love for each other through acquaintance, mutual understanding, and spiritual collision. Or maybe they met each other only once, but they felt a call, developed a love affair, and got out of hand, sublimating into love. In short, the love between men and women, in addition to retaining animal attributes at some point to carry on the family line, is more importantly a spiritual level. The love between a man and a woman is so deep and intense that they make an oath to never be separated, even if they miss each other day and night. Love is the product of connected thoughts, the product of spiritual sustenance, and the product of deep understanding of the soul. So love is a human patent. Some of the behaviors of animals have been anthropomorphized by humans, and are even used as metaphors for human love. But animals are just instincts. Animals never understand what love is. In recent years, another alternative called homosexuality has appeared. This shows that human spiritual activities are the root of love.