Nofollow' is actually good if you're using it to prevent penalties relating to link selling. Is this misleading or a fact?

Do-follow attributes is the process of passing the value of backlink to one website to another websites that is called Do-follow links. No-follow links is the process of do not pass the value to the another websites that is called No-follow link.
Example of the No-follow link:-
<a href="http://www.xyz.com/" rel="nofollow">xyz</a>
Example of the Do-follow link
<a href="http://www.abc.com/">abc</a> 

It's a fact. Adding 'nofollow' to paid links can save you from Google penalty.

Do-follow link is one that follow any link. Google always crawls the do-follow links and it is beneficial in getting good search engine results. No-follow links are one in which don't follow any link and it is not much beneficial in getting good search engine.

"No follow" is actually a site saying that it does not take liability of whatever happens if you click that particular "no follow" link.. But whereas "dofollow" is just the opposite.

Do-follow:
If you target Google and your posted links help to increase the link juice of your website then its called do-follow links. Link juice is the most important factor in promotion of your website because it help to increase the ranking and Page rank of your website.

No-follow:
If you target Google then no-follow links are waste of time because it doesn't count them as quality backlinks and if you target other search engines then it are quality backlinks and help to increase the ranking and Page rank of your website.

Do follow and no follow one of the important attribute for website. In webpage use do follow attribute means search engine crawled your page and indexed that in SERP, and its opposite if you use no follow attribute then search engine doesn't crawled your webpage. But it doesn't meaning that you never used no follow links for submitting your site. No follow site helped out for increasing traffic.

Do follow is great.

No follow is good.

So which is better? ?

do follow will boost your ranking.

no follow will make your site natural.

Each of them gives a different result that lead to Google boost ranking.