A Definitive Media Library is a secure Information Technology repository in which an organisation's definitive, authorised versions of software media are stored and protected. Before an organisation releases any new or changed application software into its operational environment, any such software should be fully tested and quality assured. The Definitive Media Library provides the storage area for software objects ready for deployment and should only contain master copies of controlled software media configuration items (CIs) that have passed appropriate quality assurance checks, typically including both procured and bespoke application and gold build source code and executables. In the context of the ITIL best practice framework, the term Definitive Media Library supersedes the term def