A downward arrow with a bar below it, marking movement by a whole screen.
Also known as: PgDn
A downward arrow above a short bar marks the page down key, the counterpart of page up: it advances the view by a full screen rather than a single line.
Marks the key that moves the view down by approximately one screenful.
Contexts: Software
A downward-pointing arrow with a triangular head, a short horizontal line drawn across beneath its tip.
Both are built from arrows, and both are used in software contexts.