Puppy Linux is an operating system for computers. Other well-known operating systems are Microsoft Windows, Apple OSX, and MS-DOS. Puppy Linux is based on GNU/Linux. It is completely free and open source software.
Linux is a free operating system, and Puppy Linux is a special build of Linux meant to make computing easy and fast.
Puppy Linux enables you to save money while doing more work, even allowing you to do magic by recovering data from destroyed PCs or by removing malware from Windows. See these example articles: recovering files from Windows and safe Internet banking with Puppy Linux.