The base construct of agile and iterative development is the iteration - the ability of the team to create working, tested, value-delivered code in a short time box - with the goal producing an increment of potentially shippable code at the end of each iteration. This is a significant challenge for the team, and mastering the process takes some time to accomplish. In this chapter, we describe the basic iteration pattern and the activities that a team engages in to meet this key challenge.