Grouping opens a submenu to control cell grouping and toggle cells open or closed.

Initialization Cell makes a cell auto-evaluate whenever the notebook is opened and the kernel is launched.

Initialization Group makes the cells in a group auto-evaluate whenever the notebook is opened and the kernel is launched.

AbsoluteCurrentValue[item] gives the absolute current value of item at a location in the Mathematica system and interface. AbsoluteCurrentValue[{item, spec}] gives the ...

ActiveStyle is an option for Hyperlink and related constructs that specifies styles to add when the constructs are active, typically as a result of the mouse being over them.

AlphaChannel[image] returns the alpha channel of image.

AutoDelete is an option for boxes that specifies whether a box is automatically deleted when its contents are edited.

Automatic represents an option or other value that is to be chosen automatically by a built-in function.

Boole[expr] yields 1 if expr is True and 0 if it is False.

ColorNegate[image] gives the negative of image, in which all colors have been negated.