Software Defined Infrastructure
Software Defined Infrastructure is the definition of technical computing infrastructure entirely under the control of software with NO operator or human intervention.
The concept refers to the ability to define your application requirements from the infrastructure (both functional and non-functional requirements) and have the landscape automatically derived and created.
Typical deployments require SDN and Cloud capabilities as a minimal point of entry.[1]
Advanced capabilities enable the transition from one configured landscape to another without downtime. Typically this will be seen as a calculated set of landscape states between one configuration and another and an automated transition step between each step. Thus achieving the complete landscape change via Software.
Additional value from SDI approach is to have versioning of your landscape enabling rollback and cloning.