What is the difference between Nofollow and No-indexing?

[Aldenhussy]

Links in blog comments – If you took the time writing a valuable blog post for your website, you do not want a competitor or link spammer to be able to add an unhelpful comment to your blog post with a link to his/her own website that says something like “Great blog. I also wrote a blog about this hot topic” and include a link back to his/her webpage so that s/he benefits from the link that person just added from your website to his/her own. If that link is set to “no follow”, a link spammer can tell that ahead of time and may not bother adding a “Great blog” comment to your blog post knowing there is no SEO value to gain from doing so.