With all the Google penalties, some people thought that they can get their competitors website penalized by sending them crap backlinks using softwares. This is negative SEO. I don't think there is conclusive evidence that it works. But it is an unethical practice even it works.
Reverse SEO is to look at your competitors backlink structure and try to copy it by getting similar links. It is commonly used by many people. You need to use backlink checkers and see why the other site is ranking where it is ranking.