The practices of ranking websites by search engines help promote any of the pages. This is why link exchange services are so popular.
Over the years, webmasters exchange links used as a means of direct marketing. Until recently, the practice of exchanging links very popular among the SEO because search engines give preference to sites that are referenced by many other sites, thereby improving the layout in the pages of issue. For search engine, the reference count is a suitable means for determining the importance of websites.
There are several ways to exchange links with other websites. The first way - send an email to another webmaster and ask him to exchange links. Another way to find websites to exchange links - visit the forum webmasters. Such websites should be forums or link exchange directories where webmasters can request link exchange a certain category or already have requests to allow any website to exchange links.
If you're new to this issue, start with the basics. There are two kinds of links: internal and external. External links - a link on your site that point to other people's websites. Internal links point to from external sites (or from your own site) on your site. So, as you have noticed, any single link is both external and internal.
Google PR (Page Rank) - an important method for determining the popularity of any website. The higher the PR of your site, the better your site is detectable in the search engine Google. The higher PR links, which link to your site, the higher rise PR of your site.
The quantity and quality of websites that link to your site (link popularity) is one of the most important factor that helps all search engines (not just Google) to determine the ratio of your site to the search phrase. Proved in practice that exchange reciprocal links with other websites extremely effective solution for webmasters looking for a way to quickly and effectively to improve search engine rankings.