SEO – Inbound Links
There are many factors that influence your position in search engine results. Inbound links (also know as backlinks or incoming links) are one indication of the popularity or importance of your website. Any time another website links to your website, that is considered and inbound link. The idea is to generate inbound links that are relative to your content. These types of inbound links are most beneficial. Beware of of link spamming or link baiting. As with any seo variable, there are good techniques and bad techniques. Inbound links directly impact your PageRank system.
Inbound links is just one of the variables that search engines utilize in their algorithms.