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

Wolfram Website opens the main Wolfram Research website in a web brower.

Word Wrapping opens a submenu of word wrapping styles

AutoIndent is an option for Style and Cell that specifies what automatic indentation should be done at the beginning of a new line after an explicit return character has been ...

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

Booleans represents the domain of Booleans, as in x \[Element] Booleans.

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

CompiledFunction[args...] represents compiled code for evaluating a compiled function.

Control[{u, dom}] represents an interactive control for the variable u in the domain dom, with the type of control chosen to be appropriate for the domain ...

EvaluationObject[n, expr, ...] represents an expression submitted for evaluation on any available parallel kernel.