Link juice in SEO – an introduction
Links, both internal on your site and external – those pointing from other sites to yours are what help search engines find and index your content. The distribution of links, particularly the quality of those linking to you and the volume is a significant search engine ranking factor. For example the bbc.co.uk linking to your site tells Google that a really influential web site is ‘voting’ for your content. Voting is a bit of an odd term to use here so it may be better to think of it that if another site feels that your content is of significance, and links to it, then that is a good reason why search engines should rank your site higher for terms relevant to that content.