Dofollow versus Nofollow

This subject has intrigued me much and I've surfed the internet a lot to figure out the difference between dofollow links and nofollow links.

Here is what I found out.

HTML

As always on the net it's all basically about HTML coding. All links are normally dofollow links unless they are tagged with some HTML code that tells search engines that it's a nofollow link, which means that they won't crawl the link and won't give the link any value as backlink. (Some say that the search engines will crawl the link but won't give the link much value as backlink).

BACKLINK VALUE

There are many factors involved in getting a webpage to rank high in the search engines but one of the main factors is backlinks. Some say that backlinks have more than 70% role of getting a webpage ranked in top but there are differences in the backlinks value so it's very important to get the right backlinks.

DOFOLLOW BACKLINKS

When searching the web most agree that dofollow backlinks have the highest value if you want your webpage to rank high in search engines. Dofollow backlinks value may also vary due to various factors which I shall not go into here but total they should have a higher value than nofollow backlinks.

NOFOLLOW BACKLINKS

But are nofollow backlinks worthless? There really are many opinions on this subject.

Some say nofollow links HAVE a value in relation to a webpages ranking.
Some say nofollow links HAVE NO value in relation to a webpages ranking.
Some say that nofollow links actually can be harmful to a webpages ranking if they come from the wrong sites.

And so on.

The value of nofollow backlinks is really difficult to figure out and surely it's only the guys at Google and the other search engines who knows the correct answer.

Personally I think both backlink types can affect a webpages ranking so I would go for both types of backlinks but mostly dofollow backlinks for a higher ranking and then stay away from anything that smells of backlink spamming.