There is a very distinct difference between do follow and no follow links. Do follow links tell the search engine bots to follow that link to the end destination. Once it gets to the end destination it will then take note of that and follow any other links on that page to any of the other and destinations that they are pointed to. No follow links tell the search engines robots to stop at that link and not to follow it to its end destination. This is often times one of the largest discussions in regards to search engine optimization because many people believe that do follow links carry the majority of the juice from one site to another while no follow links do not do that meaning that no follow links do not hold as much importance as a do follow links. Of course this is very open to interpretation and of course it also relies on a case-by-case basis as to whether or not the links will pass on any relevance. If you can find a no follow link that has a large amount of relevance of course it is worth getting that link. Because relevance is one of the largest contributing factors in current search engine optimization algorithms that help websites ranked highly within the search engines. Often times many people will pass up these high relevant no follow links but the small amount of time you can take to get these links can be extremely important and extremely influential in the overall rankings of a website within the serps.
Of course when individuals are building on a private blog network they will almost 100% of the time reliant do follow links because it is thought that these links pass on the most amount of juice from the website that is doing the linking to the target website which is often times the clients that you are attempting to rank or a money site you are attempting to monetize. I cannot disagree with this practice because I have never built a no follow link on a website that I am sending a link from to another website in the attempts to power it up. With this being said that does not mean that I will not go out and find no follow links with extreme amounts of relevance and point them to my site because of the amount of relevance and natural linking patterns that they help to incorporate into a website. This is one thing that you need to always keep in mind is the fact that the search engines are looking for individuals who stick out above the norms because they are obviously doing something that goes against the grain. You want to make sure that you have incorporated a fair number of no follow links into your linking portfolio because this helps you stay within the threshold of what is normal for sites on the Internet. If you have 100% do follow links that are all keyword anchor text this is extremely unnatural and often times it will start off a manual review or will give you a red flag which means that you will be on the search engines radar for any small mishaps you may have.
Of course the use of do follow and no follow links are completely up to the person building the links and how you are getting these links. If you are getting these links from someone who was building these link specifically for you and you have paid them then you will want to make sure that they build you do follow links. If you are on the contrary doing blog posts are asking individuals if you can do guest posting on their websites and often times these will be no follow links. This does not mean that they will not carry as much weight as the others because they are also earned links it is just telling the search engines not to follow those links to the end target which would be your website. Once again it is extremely open to interpretation whether or not no follow links pass on any juice or not because I have seen case studies or individuals point nothing but no follow links to their websites and their websites still rank because links are starting to become a thing of the past and you want to pay closer attention to user metrics. If you can send users to your website through the use of links and other tactics as long as those users are happy and the and then the search engines will take note of this and move you higher up in the serps. If you have nothing but no follow links coming from blogs and other shared type links then you will get users coming to your site and if they are happy with the content and closeout the search then it gives a positive connotation to the search engines that your site is worthy of ranking highly in the serps because it has information that is adequate and informational for the topics that are being searched. So once again it is completely up to you what links you build and often times if you are doing link outreach you will not have a choice and whether it is a no follow or do follow link. And as always, remember, keep sending links to a website until you get to the place you want to be.