The new Rules of Golf 2019 came into effect on 1st January 2019.
Click for a 9 minute video than describes some of the most important change in more detail
(when it opens up on the YouTube site, you made need to click "Skip Ad" to go straight to the video)
The links below take you to more detailed videos on specific topics and are often accompanied by additional written explanations:
BALL AT REST
THE PUTTING GREEN
PLAYING THE BALL
WHEN TO PLAY DURING A ROUND
NEW LOCAL RULE which golf clubs may adopt
For more information, see the New Rules of Golf 2019 page on this website.