SharePoint: Site Collections vs Sub Sites

I got asked this week when to use Site Collections and when to use Sub Sites in SharePoint -

 

Here's a collection of articles that should be useful.

https://www.sharepointblogs.com/llowevad/archive/2007/11/09/when-to-use-site-collections-vs-sub-sites.aspx

https://www.sharepointblogs.com/llowevad/archive/2007/06/25/site-collection-logical-architecture.aspx

https://www.bobmixon.com/blog/archive/2008/04/15/sharepoint-2007-site-collections-and-when-to-use-them.aspx