I am very new to SharePoint 2010. I have created a new site Collection named "MySiteCollection",
I want to know where this "MySiteCollection" is created? What is the physical path?
Welcome to SharePoint! Site collections don't reside on the file system at all. SharePoint magically translates the URLs and pulls everything you see from the database (some exceptions). The site collections web application is in inetpub\wwwroot\wss\virtualdirectories, but its site collections are in the database.
Is there something specific you're looking for, or to do?
This is SharePoint 101. SharePoint doesn't create physical paths, everything is virtual and based on something called Ghosting.
The page layouts are stored in the database and the appropriate templates and master page selected, the web parts and content are then generated onto the page.
Pages are then stored in the database in their cached variation in what is known as Blobs.
The template files are stored in what is known as the 14 hive for SharePoint 2010.
This hive is located in: %Program Files%\Common Files\Microsoft Shared\Web Server Extensions\14
There is the basics, you can go into much more detail if you need with Google now you know what to search for.