Backlinks are links that are directed towards your website. Also knows as Inbound links (IBL's). The number of backlinks is an indication of the popularity or importance of that website. Some search engines, especially Google takes your website and performs a mathematic equation and places a numeric value on your website depending on the back links. It will give more credit to websites that have a good number of quality backlinks, and consider those websites more relevant than others in their results pages for a search query. When people find value in what your website has to offer, thus they provide a link to your site. When search engines calculate the relevance of a site to a keyword, they consider the number of QUALITY inbound links to that site. A backlink from a site that has quality content plus content related to the theme of your site will hold you in a much better stead than a back link coming from a poorly designed or optimized site or from a site that has nothing to do with the theme of your site. So we should not be satisfied with merely getting inbound links, it is the quality of the inbound link that matters. Building quality backlinks is very important in Search Engine Optimization. It can drive traffic to your website. Link Popularity and number of backlinks are directly proportional to each other. More back links means more popularity of the site. Building backlinks is a continuous process and it will take time. There are some draw backs to this equation. If a website you are affiliated with , drop a hyperlink or a page get accidentally deleted, the Google will find a dead link and it will punish you by reducing the rank for not keeping your site up to date. Keep your website in balance with other websites you share links with. This will make Google engine happy. Adding a company that is not user friendly will not give you back links ,you may also lose points.