There are four seasons in each yearly cycle (spring, summer, fall and winter). In the Agile Software Development Life Cycle, there are 6 stages within each iteration ( plan, design, build, test, review and launch).
If you know how your application will look and function, then you can help in the planning and review phases of the agile life cycle.
As an example, think about a web app with requirements based on permissions and user roles. The first iteration of the Agile SDLC releases an application that has the users, roles and permissions combined with the ability for an admin to create, edit and delete users. The second iteration integrates modeled and structured data into the users browser (the view). The ability for any user to view, create, edit and delete data is dependent on the users role and the permissions attached to this role.