What is a spiral life cycle?

Spiral life cycle - An IT system’s development model that aims to learn from experience by drawing from both iterative development and the waterfall model. It has four sequential phases: identification, design, construction, and evaluation and risk analysis. At the end of each life cycle, an iteration is assessed by the customer, and the spiral sequence begins again upon receipt of customer feedback. The spiral model is typically used in long-term projects or those where requirements are expected to vary, and customer feedback is to be incorporated in phases