The standard FreeCAD menu allows access to functions which are used in all workbenches. Your menu may look slightly different depending on your desktop environment (KDE, Gnome, Windows, OS X, etc).
The File option provides functions related to input and output, such as Open, Print, Export, etc.
The Edit option provides functions related to changing the model, such as Copy, Paste, etc.
The View option provides functions related to the display of the model, such as which panels to show, Zoom, etc.
The Tools option provides functions for debugging models and customizing FreeCAD's behaviour.
The Macro option provides functions related to the recording and execution of groups of FreeCAD commands.
The Measure option provides functions related to the Delta and/or 3D distances. This menu appears only in the Part Workbench.
The Windows option allows for switching between and arranging open FreeCAD windows.
The Help option provides access to the FreeCAD help system and provides information about your FreeCAD installation.