I am using SharePointe 2010, and newbie with sharepoint. I am trying to create site collections by using powershell and c#. my client wants to have different urls for each site collection within same web application something like (sc1.domain.com, sc2.domain.com ....) is it possible? thanks
To get what you're after (unique FQDN for each site collection in the same web application) in a supported manner you'll need to use host-named site collections (Plan for host-named site collections (SharePoint 2010)). In addition to the TechNet documentation, another great primer can be found at What Every SharePoint Admin Needs to Know About Host Named Site Collections.