Link Building (External)
What is External Link Building?
External link building is the process of building links from another domain to your domain to increase the relevance of your content. The content from the incoming link should be related to the content on your web page.
WARNING: Do not buy links!
Buying links is a tactic of black hat SEO. Many online SEO businesses offer link building services but be careful about who you choose. Link building should be organic and if Google picks up on links bought from low quality websites it could have a detrimental effect on your search positions and even result in you being excluded from the rankings.