The Smart Client uses two different types of windows tool windows and document windows.

Tool windows can be docked, floated, auto-hidden, or moved to an optional docking area. They can be dragged to new locations and attached to each other to form tab groups. Complex hierarchies can be created and each control in the hierarchy has the ability to be resized via a splitter. Tool windows can also be displayed as document windows.

Document windows are typically displayed in tabbed document window areas, but can also be floated. They are intended to have a shorter lifespan than tool windows.

Tool windows can only be started once, e.g. you can only start one Domain Explorer. Document windows can be started several times. E.g. you can open several View windows editing different views at the same time.