Getting Back-Links and adding One Way Links
A link that a site has gotten from another site is called a Back-Link. If a site has more Back-Links it has more value and the chance of it being found when the subject matter is searched for increases. So its placement in SERPs (Search Engine Result Pages) rises due to its higher rank. Sites that want to be found in search engines, especially in Google, need to have a good amount of Back-Links.