There and a great many of these which I shall detail but the basic ones Name: and Type: for file name and file type respectively would be used in the format…
…if you were looking for Adobe Acrobat files. This is a way to help narrow down searches.
Kind: used to search the properties of a document type
Datemodified: to search by the date a file was modified
Type: to search by file type
Name: searching by file name or by a property name for a file
Or type kind:music OR kind:pictures OR kind:videos
Microsoft really should have done better with search in Windows 7. Fortunately there are alternatives, such as Copernic that still offer better search functionality.