when I created a Sharepoint site collection on the root. it comes out as
What are this Sites means?
Is it possible to create a site's collection without having Sites in the URL?
Sites/ is a Wildcard Managed Paths which specify that one or more site collections exist at a specified path!
There are two types of managed paths that you can create:
wildcard inclusionallows you to append multiple site collections to the path that you specify.
explicit inclusionallows you to create a single site collection with the specified address.
For more details check Managed Paths in SharePoint
Is it possible to create a site's collection without having Sites in the URL ?
Unfortunately, you can't create/control
Managed Paths in SharePoint Online. but you can only manage it in SharePoint On-Premises