This document discusses configuration management and the Puppet configuration management tool. It begins by explaining the problems that arise without configuration management, such as difficulty rolling back software changes and inconsistencies between environments. It then defines configuration management as systematically handling changes to maintain system integrity over time. The document introduces Puppet, describing its master-slave architecture where configurations are pulled from the master node by agent nodes. It provides an example of using Puppet to deploy MySQL and PHP across multiple servers. Key Puppet concepts discussed include resources, classes, manifests, and modules used to define and apply configurations.