Window > Tile Windows Wide (Mathematica Menu Item)

Tile Windows Wide arranges all windows to fit in the screen one above the other (Windows and Macintosh only).

Help > Virtual Book (Mathematica Menu Item)

Virtual Book opens the Wolfram Mathematica Virtual Book, an updated and expanded electronic version of The Mathematica Book.

Help > Welcome Screen... (Mathematica Menu Item)

Welcome Screen opens the Welcome Screen, which appears by default each time you start Mathematica.

Format > Word Wrapping > Wrap at Paper ... (Mathematica Menu Item)

Wrap at Paper Width wraps lines at the width of the paper currently specified by the print settings.

Format > Word Wrapping >  Wrap at ... (Mathematica Menu Item)

Wrap at Window Width wraps lines at the width of the window containing the text.

AbsoluteFileName (Built-in Mathematica Symbol)

AbsoluteFileName["name"] gives the full absolute version of the name for a file in your filesystem.

ArrayComponents (Built-in Mathematica Symbol)

ArrayComponents[array] gives an array in which all identical elements of array are replaced by an integer index representing the component in which the element ...

AutoOpenPalettes (Built-in Mathematica Symbol)

AutoOpenPalettes is a global option that specifies the palettes that are automatically opened when Mathematica is started.

Begin (Built-in Mathematica Symbol)

Begin["context`"] resets the current context.

CellFrame (Built-in Mathematica Symbol)

CellFrame is an option for Cell which specifies whether a frame should be drawn around a cell.