what is difference between dofollow and nofollow?

Dofollow means search engines will follow the URL in link and give SEO benefit to it and Nofollow means that the search engines will not follow the URL in link and there will be no SEO benefits.

this is simple because do follow means search engines follow url link and seo benefit with dofollow and nofollow means search engines not follow the link and there no benefits for seo. that is why everybody need dofollow not nofollow. 

Dofollow means search engines will follow the URL in link and give SEO benefit to it and Nofollow means that the search engines will not follow the URL in link and there will be no SEO benefits, but although that u will need them both

This issue of do-follow and no-follow is not clear to me and I’m still trying to learn. I am thankful for finding this kind of discussion that at least I am getting a clearer idea of what those URL means. To be honest, I don’t know how to spot a do-follow or no-follow URl that I hope I can see an example later.