Inbreeding in plants happens when closely related plants mate, leading to a loss of genetic diversity. On the other hand, heterosis, also known as hybrid vigor, results in hybrids having better traits than their parents. This can include increased size, fertility, and seed yield. While these concepts have been around for a long time, there is no one agreed-upon theory. Different types of heterosis and how it can be fixed in plant breeding are also discussed in the article.