To link to a website, you first need to find a few high quality websites. Link is divided into internal links and external links two ways, internal links refers to the same site between the pages of each link. External links, also known as exchange links, refers to the site between the import and export links. In the site link optimization, to find more well-known, a large number of visitors to the site to import links, and pay attention to control the number of export links.