Blog backlinking is a free way to provide backlink. Adding links to comments on blogs with high page rank is called blog backlinking.
Firstly, the pages in the blog are divided into do-follow no-follow segments. Dofollow is a page that shows the link output that Google sees fit. So, they are recommended link outputs. Dofollow pages are pages that give link outputs recommended by webmasters (blog owner webmasters) Nofollow is a linking format where the owner of the blog has no connection to the linked website. Both linking types are useful for Google rankings.
Don’t add your recently opened websites to blog backlinking!
We all witness the sad result of people who add websites which got opened just a day ago to blogs with 50-60 pr. Don't ever add a new website which doesn’t have any content to blogs.
Let me try to explain the two most important rules in blog backlinking with these two small pictures:
The reason is that, the website is already providing link on the top. You don't need to add link again (comments as shown in the second picture are the comments which are not approved by the blog owners).