vim scroll document without moving cursor code example

Example: vim scroll without cursor movement

Ctrl-y Moves screen up one line
Ctrl-e Moves screen down one line
Ctrl-u Moves cursor & screen up ½ page
Ctrl-d Moves cursor & screen down ½ page
Ctrl-b Moves screen up one page, cursor to last line
Ctrl-f Moves screen down one page, cursor to first line