Dofollow links allow Google and other search engines to return traffic to your website or blog. As a result, every time you add a do-follow link to your site, it can point back to you, bolstering your authority by displaying to search engines which other sites, blogs, and postings are connecting to you.
For example, if some Content employs a do-follow link from Company X on its blog, the page or blog post linked to will be considered in the ranking. Some people refer to this as "Link Juice," and it arises as a result of Google's PageRank statistic. As a result, when adding external links to your blog, make sure they come from sites with high authority, as this will help your blog's authority develop.