Like spitfire said. Centrino is a package that includes the Pentium-M, a chipset, and a wireless networking solution. It's like asking "what's the difference between an engine and a drivetrain". The Centrino package contains the Pentium-M processor, which is also available separately.
<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>