Puppet is system administration — Automated.

By saving you countless hours of frustration, monotony, and/or reinventing the wheel, Puppet can change your life. Here are some key points about Puppet:
Puppet speaks the local language

Puppet lets you perform normal administrative tasks (such as adding users, installing packages, and updating server configurations) on any number of systems, even if those systems are running completely different operating systems. Through the use of providers, Puppet takes a generic instruction from you (such as ensuring MySQL is installed) and performs the task the "right way" for each system.
Administer One Server or 1,000

Whether you have a small, heterogeneous network of user workstations or a cluster of rack-mounted number-crunchers, Puppet can help reduce your overhead and get the everyday management of your network under control so you can concentrate on the real problems.