Short Development Cycles, Iterations, and Timeboxing

A development cycle is defined by a timebox and results in a predetermined outcome. The length of the timebox depends on the state of the project, among other things.

Release cycle

A release cycle is a development cycle with a determined outcome, called a release (of software). Sometimes, teams like to distinguish between internal and external releases. Both should result in working, usable software, but only the external release is intended for delivery to the customer, whereas the internal release is just that—internal—and stays inside the company. However, even an internal release has to go through all the acceptance tests that the external release goes through, so there is no real difference in quality or functionality between an external and internal release. The internal release usually only includes the working software. Rarely does it consist of other required artifacts, such as documentation, as well.