The term that ICE uses for the data structure of the drawing.

At a very high level the user is constructing a "solution" that is a tree of all the elements in the drawing. The 2D view, 3D view, etc. are all just different views of the data that makes up the solution.

There are many specialized reports that are specific views of that data--the Glass Report or MSGR for example. When a product is selected in the palette and is drawn in the plan view, it is added to the solution tree. When it is modified, the solution 're-solves' and changes any data necessary in the solution tree, and the different views (plan, 3D, Quote, etc.) are regenerated.