A site collection is a group of Web sites that have the same owner and share settings (i.e., permissions). When a site collection is created, a top level site is automatically created in the site collection. One or more subsites can be created below the top-level site.
*Taken from Microsoft Technet.
**See Site Collection vs SubSite.
Article ID: 781, Created: October 30, 2013 at 12:39 PM, Modified: August 12, 2019 at 5:07 PM