Visual Framework
Wireframes outline the basic content and functionality of an interface, minus the final UI design elements. They are in depth enough to fully consider user needs and user journeys, but at this stage, disregard the final visual design. Having said this, wireframes can explain a lot about how the user would interact with the interface. Simple details such as shading buttons can be used to highlight interaction points, clearly presenting the content and structure as well as interaction and flow.