Line-by-Line Scroll

Ctrl-E and Ctrl-Y — scroll without moving the cursor (until you have to).

Keys: Ctrl-E, Ctrl-Y

Ctrl-E scrolls the screen down one line; Ctrl-Y scrolls it up. The cursor stays on its file line until the screen would have to push it off — then it moves with the screen.

When you want to peek at what's just off-screen without moving the cursor, Ctrl-E and Ctrl-Y are the right tools. They scroll the viewport one line at a time and leave the cursor where it was — until the cursor would scroll off, in which case it slides with the screen.

Reference

See also: Half- and Full-Page Scrolling, Centering the Cursor