Currently scrolling moves the cursor position. In Vim the relative cursor position doesn't move.
Try it in Vim and comparing it to ST. The difference is not difficult to see.
CTRL-D Scroll window Downwards in the buffer. The number of
lines comes from the 'scroll' option (default: half a
screen). If [count] given, first set 'scroll' option
to [count]. The cursor is moved the same number of
lines down in the file (if possible; when lines wrap
and when hitting the end of the file there may be a
difference). When the cursor is on the last line of
the buffer nothing happens and a beep is produced.
See also 'startofline' option.
{difference from vi: Vim scrolls 'scroll' screen
lines, instead of file lines; makes a difference when
lines wrap}
Currently scrolling moves the cursor position. In Vim the relative cursor position doesn't move.
Try it in Vim and comparing it to ST. The difference is not difficult to see.