Desired State Configuration (DSC) is a feature in PowerShell 4.0 and Windows Server 2012 R2 that helps Windows administrators manage and deploy software services' configuration data and the environment the services run in.
DSC provides a set of PowerShell language extensions, cmdlets and a process called declarative scripting. The idea behind Desired State Configuration is to provide administrators with a method for maintaining consistent configuration sets across computers or devices. Administrators can write an expression about system configuration, and the system figures out how to make the configuration work.
When used correctly, DSC can help an organization avoid configuration drift, which can occur if an application on one machine modifies a default settings to make its configuration different from its sister machines.