About the relationship between links and Googlebots
Googlebots, also known as Google Spiders, act like spiders patrolling the spider’s web of websites, as the name implies. At that time, Googlebot follows the “link” that corresponds to the spider’s thread.
Properly patrol this link will increase the frequency of Googlebot patrols and begin to show SEO effects. Therefore, if you connect pages related to each other with internal links within your own site, or if you receive external links from an authoritative site, you can expect an increase in the frequency of crawler patrols and the accompanying increase in access.
However, “purchasing an external link” is illegal. Obviously unnatural external links are considered spam and are subject to penalties. From the SEO point of view, it is important to increase the number of external links in a natural way.