In the second step, you have to review and clarify your ideas, think about what they mean, and if they are actionable. After that, you decide on the next actions and projects. In this method, projects are any tasks that require more than one action. If you decide it's not actionable, you can: trash it, use it for reference, or put it on hold.
Here we have another great episode from the GTD podcast where David talks about this step; you can start at 1:25: