What makes the trackpad scroll in the opposite direction after an update?

After a recent update, scrolling on my laptop's trackpad feels reversed: moving two fingers up makes the page go down, and moving them down makes it go up. Is this an intentional setting change, a driver issue, or a bug, and how can I restore the scrolling direction I had before without affecting my mouse or other touchpad gestures? Please let me know what details, such as my Windows version and laptop model, would help troubleshoot this.