Are aware you can show information in Revit in a variety of ways, from 3D views to plans, sections and elevations. In each case the geometry is typically modelled based on design intent, meaning the goal isn’t to model everything but model enough to demonstrate what the building is going to look like.
It then becomes necessary to add 2D details to bridge the gap between the design and building reality, conveying information to the builders and contractors on how a design should be built. Architects and engineers create standard details to represent how materials in the larger project are constructed. Details are vital additions to a project, because they show how materials should interconnect.
There are 2 main types of views you can create for detailing: detail views and drafting views.
A detail view can be created as a section or a callout and we can create a callout from a plan, section, or elevation view and then add detail components while using the model geometry as a base. When you create a callout or section detail, you can also reference another detail or drafting view in the model.
For example, a simple building with a pitched roof which might already have facia boards soffits and guttering placed, because we have tools to do these in 3D. We now might want to create the Eves Detail.