Robots.txt is not an appropriate or effective way of blocking sensitive or confidential material. It only instructs well-behaved crawlers that the pages are not for them, but it does not prevent your server from delivering those pages to a browser that requests them. One reason is that search engines could still reference the URLs you block (showing just the URL, no title or snippet) if there happen to be links to those URLs somewhere on the Internet (like referrer logs). Also, non-compliant or rogue search engines that don't acknowledge the Robots Exclusion Standard could disobey the instructions of your robots.txt. Finally, a curious user could examine the directories or subdirectories in your robots.txt file and guess the URL of the content that you don't want seen.
He is the co-founder of Neil Patel Digital. The Wall Street Journal calls him a top influencer on the web, Forbes says he is one of the top 10 marketers, and Entrepreneur Magazine says he created one of the 100 most brilliant companies. Neil is a New York Times bestselling author and was recognized as a top 100 entrepreneur under the age of 30 by President Obama and a top 100 entrepreneur under the age of 35 by the United Nations.
Matt, I’ve been a firm believer of the thought that webmasters shouldn’t really bother too much about the calculations that Google would do while spotting external links on a site. Leave that to Google. You write the content and if you find relevant resources, link to it. Why worry over PR ? In case you’re so sure about the linked site to be “kinda spammy” then nofollow it. That’s it.
PageRank has been used to rank spaces or streets to predict how many people (pedestrians or vehicles) come to the individual spaces or streets.[51][52] In lexical semantics it has been used to perform Word Sense Disambiguation,[53] Semantic similarity,[54] and also to automatically rank WordNet synsets according to how strongly they possess a given semantic property, such as positivity or negativity.[55]
Things are constantly changing, there is even evidence that nofollow links do count on some occasions. Its really a very complex subject as there is a formula behind the algorithm that takes many factors into consideration trying to guess what factors come into play is very difficult. I always focus on making the site as useful as possible to as many people as possible this is the end goal for search engines as well as webmasters. Webmasters who do this whilst observing the search engine’s guidelines should not have problems in reaching the top.
A breadcrumb is a row of internal links at the top or bottom of the page that allows visitors to quickly navigate back to a previous section or the root page. Many breadcrumbs have the most general page (usually the root page) as the first, leftmost link and list the more specific sections out to the right. We recommend using breadcrumb structured data markup28 when showing breadcrumbs.

Search Engine Optimization