Continuous delivery is a software engineering approach that produces software in short cycles, so that the software can be reliably released at any time. ^_Wikipedia

"Continuous Delivery (CD) is a software strategy that enables organizations to deliver new features to users as fast and efficiently as possible. The core idea of CD is to create a repeatable, reliable and incrementally improving process for taking software from concept to customer. The goal of Continuous Delivery is to enable a constant flow of changes into production via an automated software production line. The Continuous Delivery pipeline is what makes it all happen.

"The pipeline breaks down the software delivery process into stages. Each stage is aimed at verifying the quality of new features from a different angle to validate the new functionality and prevent errors from affecting your users. The pipeline should provide feedback to the team and visibility into the flow of changes to everyone involved in delivering the new features."

-- Andrew Phillips, The Continuous Delivery Pipeline — What it is and Why it’s so Important in Developing Software.