Bracket feature?

[Shiny K]

If you hold down the bracket keys[], it only allows you to draw in an area relative to your cursor.
[ is perfectly vertical to it, and ] is perfectly horizontal. why does this exist and what can I use it for?

[Dav999]

You use it for drawing straight lines much faster without risking drawing it askew or with all kinds of bumps.

[Shiny K]

oh ok