Why might you want to use nofollow on an internal link?

[Patelsharp]

Why might you want to use nofollow on an internal link.

[Garima Sharma]

A 'no follow' will be beneficial as there will be less number of links on your webpage to share the juice. But at the same time it will help your visitors to visit the pages that are linked internally.Nofollow doesn't stop Google from crawling pages, it stops any 'link juice' being p***ed to those pages.
Robots.txt is what you want to prevent google from crawling pages.

[Mohit Rana]

Using the "nofollow" attribute on an internal link within a website is a practice typically employed for specific reasons:

1. Crawling Efficiency: Internal links are often used for navigation within a website, guiding users from one page to another. However, search engine crawlers also follow these links to index content. By adding the "nofollow" attribute to certain internal links, you can prevent search engines from wasting resources crawling less important or redundant pages, thereby improving the efficiency of their crawling process.
2. PageRank Sculpting: In the past, website owners attempted to manipulate the flow of PageRank (an algorithm used by Google to rank web pages in their search engine results) by strategically applying "nofollow" attributes to internal links. By doing so, they could attempt to concentrate PageRank onto more important pages of their site. However, it's worth noting that Google has adjusted its algorithms over time, and the impact of PageRank sculpting through internal linking is now much less significant.
3. Avoiding Duplicate Content: Sometimes, internal links might lead to pages with similar or identical content, such as printer-friendly versions, archive pages, or parameter-based variations of the same content. Adding "nofollow" to these links can signal to search engines to avoid indexing these duplicate or near-duplicate pages, reducing the risk of being penalized for duplicate content.
4. User Experience: Although less common, there may be instances where you want to include internal links for user navigation purposes but prefer not to influence search engine rankings for those specific pages. For example, you might link to a login page, a terms of service agreement, or a page with less relevant content. In such cases, adding the "nofollow" attribute can help ensure that these pages aren't given undue weight in search engine rankings.