A new scrollbar responds to the mouse. You can click or drag its handle, or click the track it runs along, to scroll. It lights up when the pointer is over it.
Why
Where this scrollbar appears, you can scroll with the mouse instead of only the keyboard.
How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtThe finding does not say which screens use this scrollbar.
