The developing of a brand-new web site, or its redesign, always starts with a prototype of the graphic. And because a picture is worth a thousand words, is always more useful to sketch the site interface than describing it in a document.

But what is the right tool to choose, when building a prototype? Well, it depends on the problem, and on the status of the project. A single prototype will never be sufficient for the customer to understand how the site will be: for each phase of the project design, there’s an appropriate tool. This article explains them all!

via Match the Tool to the Problem – 52 Weeks of UX.