We know that there are two types of SEO. One is On page and another is Off page SEO. Creating backlinks is the most important task of off page SEO. To take your website on top of the search engine you need to use the URL of that site on high Page Rank sites. Let me clarify that along with the importance of creating backlinks.
Take for example you have 2 websites and the name of the sites are A and B. Suppose site A has a link and if you click that link then it will take you to site B. This can be called that site B has a backlink at site A. The result is, visitors from site A can visit site B and likewise people from site B can visit site A.
Backlinks can have NoFollow or DoFollow tag. Generally, if your site is linked with another site and if the search engine bot crawls that site then it will also visit your site through the backlink. If that page has Page Rank then your linked page will also receive good page rank of that page by a ratio. If someone visits your site and put a comment on your article or post and leaves off a link to his/her site, this is also a way to get a backlinks. However, if you don’t want to give away your page rank of link juice to those who do this, you can stop that by using the NoFollow tag. To do so, you need to use this code in your website’s backend,
<a href=”//www.sitename.com”” rel=””nofollow””>Site Name</a>
This code is very useful and used in the link that people drops in the comment section. It prevents unwanted people or spammers to achieve page rank of their sites. It also discourages visitors to put irrelevant comments. In some sites, there is no spamming feature, on those sites its better not to use NoFollow tag. Because it will inspire people to put comments and communication will be better with your site. Furthermore, if Google finds out that you have used DoFollow tag on a low ranked website then Google can give penalty to your site. So be alert what you follow and what is following you.