First of all you will create a web application with URL looking like this, (HostName as referenced by yourself)
portal.companyName.com //we call it host header, this URL looks like a intranet
www.companyName.com //if its going to be a public site
Then you create Managed paths, which you referenced as Drop Down List in your question.
I just found this picture will help you understand better,
Managed paths, well, manages the paths. That might sound a bit funny,
but it’s true. Within SharePoint, you cannot create a site collection
just anywhere you want. You have to attach a site collection to a
The biggest benefit of doing this is that it helps keep SharePoint
manageable from the user’s perspective. You don’t want site
collections to be created haphazardly. There should be some logic
applied to the structure. In highly structured environments, a
SharePoint steering committee can specify the managed paths that
should be used. Policies then prohibit the addition of new managed
paths without committee approval.
When administrators create new site collections, they are unable to
create them outside of where the managed paths define.
I have to show from a drop down list so this means that site
collection should exists below a site?
You need to create a managed path for the site collection, however you can create a root site collection though, e.g. in above picture you can create your site collection at
When we are not planning to create further site collections under a
specified managed path, then we use this option. Explicit Inclusion
Managed paths allows in creation of only one site collection at the
exact given URL. In our case fahadexplicit would be the only site
collection that can be created. SharePoint will allow creating only
one site collection within this Managed Path.
The URL would be:
When we want to create more than one site collection under a specific
managed path, we use this option. Wildcard Inclusion Managed Paths
allow unlimited site collection to be created under a given URL. In
our case under fahadwildcard, we can create any number of site
The URL of these site collections would be as below: