Off-page SEO - definition
Off-page SEO deals primarily with your site’s relationship with other websites outside your domain – or more accurately their relationship with your site.
Among other factors, search engines judge the relevance and authority of your website through the inbound links it receives from other sites. The quality and quantity of the site that is passing the incoming link to you will determine the SEO significance passed.
Those sites’ own authority, judged similarly by the quantity and quality of their own incoming links, pass along search engine recognition that improves the search significance of the receiving page, hence the term off-page SEO.
When a website links to yours, search engines interpret that as a real-life vote of confidence that your website can provide some sort of expertise or further explanation of a topic being discussed on the host site. This supports the idea that good, relevant content is the best way to achieve good search engine results.
Read more in this blog post:
Off-page SEO - building real estate links