The Edit menu has the following options:
Undo - Undo the last thing (action) you did (). Mainly all actions are undo-able.
Redo - Undo the last thing you undid ()
Cut - Cuts (copy and delete) the selection ()
Copy - Copy the selection ()
Paste - Paste the selection ()
All of these actions are global. They not only work on the Canvas, but also in the Layers Palette, Parameters Palette, etc...
Select all layers
Select all layers - () - selects all layers
Deselect all layers
Deselect all layers - () - deselects any selected layer(s)
Select all handles
Select all handles - () - selects all of the handles on the selected layer(s)
Deselect all handles
Deselect all handles - () - deselects all of the handles on the selected layer(s)
Input Devices - opens a the Input Devices dialog that allows the user to setup custom values related to the input devices, generally the mouse but also for graphical tablets and other pointer systems.