To understand blogging for backlinks you have to understand how each of these functions to create a pathway for the other. Online it is important to have quality blogs built so people can read them and learn from them. Blogs that are informative and valuable become important to search engines. Search engines have one simple product. Your blogs, your pages, your sites content. A good blog with a link back to another site is a great way to get Google to like your site or see it as valuable. When your blogs link to other sites this is a popularity thing.