Menus offer the user functions to apply to the current selection, the layer, the image as a whole or the software environment.
Menus regroup items representing functions of similar nature, often requiring further information, and sometime proposing keyboard shortcuts to access them.
NOTE: Item with ellipsis 
the ellipsis (...) that follows a menu item indicates that further information is required in order to complete its function.
NOTE: Keyboard shortcuts 
Menu items that can be invoked by keyboard shortcuts specify at the right margin of the given item what keys are involved. For example, the item "Edit/Deselect all" shows Ctrl+D as the key combination to use so that by pressing both the Ctrl key and the D key simultaneously you are in fact calling this menu item.