'Do follow' links are crawled by search engine bots and thus they contribute to website backlink building.
Example: <a href=”
https://www.brotherlabs.com/in/” rel=”dofollow”>E-commerce website development</a>
'No follow' links are never crawled by search engine spiders and hence they do not contribute to back-link building. Both types of links are used to build traffic for your website and help in keyword ranking in search engines.
Example: <a href=”
https://www.brotherlabs.com/in/” rel=”nofollow”>E-commerce website development</a>