No Follow Tags

Link building is a huge part of SEO and increasing PageRank, however you need to be careful that you are only increasing your own backlinks and nobody else's.

By entering an external link into your site you are giving that website landing page a backlink, known as a vote, to disregard this vote, you need to;

Click the view the Source when entering content, and then enter this text; rel="nofollow" after the link, for example;
<a href="http://www.example.co.uk"> rel=”nofollow”</a>

SEO Specialists use no follow tags when entering external links into content. This way users will still be able to click the link that will take them to the right page as usual, only search engine spiders will not be able to crawl the links and so it will not drain your PageRank. Experts know that losing your PR to 'no-money' pages will not help your SEO improve on the pages that matter to your business.

This is not applicable to internal links as you will be voting for your own cause!