Backlink

Every link from an outside domain to a page on your site is a backlink. Search engines have used them as a vote of confidence since the earliest days of PageRank, and they still carry weight, though relevance and the linking site's own standing matter more than raw count. Creators run into them when they build a website alongside the channel: a podcast directory listing, or a resource page on somebody's blog. Paid link schemes and mass directory submissions are treated as spam by Google and can cost you rankings instead of winning them. One genuine mention from a site in your subject area beats 50 from places nobody reads.