In SEO, Contextual links refer to the backlinks found within an article or content. It is basically any clickable link within the content body itself. For example, the links highlighted below in the red box are known as contextual links.
Unlike links placed in the sidebar, header, or footer of the website, contextual links carry more SEO value and consider as more relevant links. Google gives more weight to contextual links and having an established website or blog link back to your website definitely gives a good boost and helps you more.