Which basically mean where I could specify more than just a file name;
Search in Windows 7 does not just operate on filenames. It will also search inside of any document that it knows how to read (.doc, .xls, .pdf, emails in Outlook, etc). It's also very customizable by what you want to search and prioritizes results differently based on where/how you're searching.
Here's a couple of links that might help you:
You have to use search filters in the search bar in order to specify filetype, filesize, etc.
To search based on file extension, you'd can add ext: to your search
This will only show you results that are PDF files.
For a list of search filters you can check out this article: http://www.microsoft.com/windows/products/winfamily/desktopsearch/technicalresources/advquery.mspx