Some of the crawled URLs are automatically getting grouped. How are the groups getting created?

While discovering the URLs of the website, Milestone Schema Manager groups pages based on their URL structure and Document Object Model (DOM). If pages are found to similar these bases, they are grouped together. 

Now, once the auto discovery is complete, under the ‘Schema Audit’ Tab, you will see the list of URLs. URLs with a certain number signifies that the URLs have been grouped. The pages that have been grouped together will have a certain number against the URL which signifies the number of pages that have been grouped.