The basic organization of Slicer's user interface (UI) is shown above. This module's content will reference these following components, labeled in the figure:

File Menu:
Contains basic load and save functionality, access to application settings, Tcl and Python interfaces for developers, help and mechanisms for users to provide feedback.
Toolbar:
Contains tools for selecting and navigating among Slicer modules, layout and other utilities.
GUI Panel:
Contains a UI for any selected module.
Slices Controls:
Contains a UI to configure the Slice Viewers. This panel can be collapsed if you need more room for the GUI Panel.
3D View Controls:
Contains a UI to configure the 3D Viewer. This panel can also be collapsed if you need more room for the GUI Panel.
3D Viewer:
Displays a rendered 3D view of the scene along with some visual references to clarify its spatial orientation (A = anterior, P = posterior, R = right, L = left, S = superior and I = inferior).:
Slice Viewers:
Three default slice viewers are provided (Red, Yellow and Green) in which Axial, Saggital, Coronal or Oblique 2D slices of volume images can be displayed.
Progress & Error Log:
Displays progress feedback for most processing operations. If an error occurs, the icon in the lower right corner provides access to the error log. (The information it contains is useful for providing feedback to the developer community).