Natural link structure is a common word for the search engine optimization services. These services accentuate how important it is to have a natural link structure. What in the name is a natural link structure?. It means having no "artificial" links. If this is the case there will be no progression to achieve high rankings.
Variety of links pointing to a site with various anchor texts pointing to different web pages can increase natural link structure. Most famous sites, which have natural link structure are Wikipedia.org and Youtube.com. These sites doesn't ask people to link to their sites.
To achieve more natural link structure you need to attract visitors to link to your site, just like those sites like Youtube.com and Wikipedia.com. To attract to get other web sites link to your site, web masters need to find out what people really move to link to your sites. If you have valuable information for the visitors, then web masters and bloggers will link to your web site. Using link bait can attract visitors and also can generate backlinks. Wikipedia.org takes the crown ranking high for every search term in the search engines. This is the outcome when a site has variety of links pointing to a site. A part of the search engine optimization is building natural links pointing to your web site through directory submission, article directory submission, commenting on relevant blogs, press release.
If you have a site about Iphones, then adding variety of anchor texts like "Iphone supplies", "Iphone functions", "Iphone covers" can increase your web rankings.