Undo: Restores the picture before last change. Actually, the undo command restores pixels changes: it does not apply to Selections because they have their own undo command.
Redo: The opposite of undo command: restores the changes made to the picture. It does not apply to Selections because they have their own redo command.
Resize Project: Allows to change size of the project by resampling the picture.
Resize Canvas: Allows to change size of the project by enlarging or decreasing its canvas.
Copy: Copies to memory the content of the current selection or the whole work area and creates a new object. An Object can be promoted to an image layer by the command Edit>Paste as new layer. There are also other ways to create objects, like importing from file (see further commands).
Cut: Same as Copy but also cuts away the copied region: when used with Image Layers this command modifies the layer alpha channel. When used with the background the region is filled with white color.
Paste Object as new layer : This creates a new image layer from current object in memory. An other way to create a layer is choosing: Layer>Image Layer>Create new.
Paste from Clipboard as new Layer: Similar to the previous command, but uses directly the content of the Windows clipboard, for example when you copied a picture from another application.
Crop to Work Area: This crops the picture to the work area: It can apply to the background or the current image layer.
Resize to work Area: This resize the current image layer or the background to the extent of the work area.
Revert to Original: Restores the Background Picture as it was loaded from file the first time.
