An iteration is a set period of time, usually 1-2 weeks, in which a product team works on a specific set of tasks or features. It is a key concept in agile software development methodologies, such as Scrum, that emphasize the importance of delivering small, incremental changes to a product on a regular basis. This allows teams to quickly test and validate new ideas, gather feedback, and make improvements based on user needs. Iterations are a key part of the product development process and help teams, including UX/UI designers, engineers, user experience researchers, and product managers, to create great user experiences on websites and apps by continually improving and refining the product based on user feedback.