In this chapter they discuss the skeleton plane. The book goes into describing interface design, navigation design and information design. A skeleton plane defines what form the functionality of a product will take. Interaface design is important for overall design. It is responsible for the buttons, fields and overall interface components. Navigation is how one gets around a cite. The design is tailoring the interface to a space for information about controlling and moving around. Information design is all about the meat and potatoes of the cite. This part of the design is for the information and making it as effective as possible to bring the communication across.