Definition:

In search engine optimization (SEO), backlinks refer to hypelinks pointing to a particular Web page. Backlinks are important to SEO, because Google considers the quality and quantity of backlinks to determine PageRank which is one of more than 200 ranking singles used by search engines to order results for a given keyword.

To be clear, backlinks aren't the single determining factor for search rank, but they are a factor that's often abused for cheap boosts in Google search results.

Google is constanly tweaking their search ranking formulas in order to weed out pages that earn their rank through cheap tricks.

As an example: Overstock.com and JC Penny's ran into trouble for creating an artificial web of backlinks in order to inflate their ranking. (To be absolutely fair, it was likely the marketing firms they hired that did the rogue backlinking, not the companies themselves.)

If you'd like to get backlinks the legitimate way, Google suggests creating great content that people want to link.

Also Known As: inbound links