When using the keyboard, you move about the screen using the arrow keys. The left and right arrows move you along the horizontal axis (which of the axes is “horizontal” depends on your view angles). The up and down arrows move you along the vertical axis. Press and hold the Shift key while using the left, right, up, and down arrows to move along the horizontal and vertical axes in smaller increments or “steps.” To move in the third direction, press the Ctrl key in combination with Home or End. To move the cursor in smaller increments in the third direction, press Shift in combination with the arrow keys or Ctrl+Home or Ctrl+End.
You can also specify the size of the cursor movement when using the arrow keys. Use the Options / Cursor command to set the Large Step Size (regular arrow keys) and Small Step Size (Shift+arrow keys) to convenient values.