Continuous Delivery is the software engineering practice wherein production-ready features are produced in a continuous manner.
When we say production-ready features, we mean only those features that have passed the following check points:
Unit testing
Integration
Static code analysis (code quality)
Integration testing
System integration testing
User acceptance testing
Performance testing
End-to-end testing
However, the list is not complete. You can incorporate as many types of testing as you want to certify that the code is production ready.
From the preceding list, the first four check points are covered as part of the Continuous Integration Design discussed in the previous chapter. This Continuous Integration Design, when combined with deployments (not listed here) and with all sorts of automated testing can be safely called Continuous Delivery.
In other words, Continuous Delivery is an extension of the Continuous Integration methodology to the deployment and testing...