When the USGA and R&A made the significant rule change in 1952 to allow golfers to mark their ball on the green, golfers suddenly needed something to mark their ball with.
The term golf ball marker denotes a small flat object designed for marking the place on a putting green where a golf ball is lifted from. In recent times, it's also been used to refer to devices that golfers use to add identification marks or any kind of marks on their golf balls.
As part of the rules of golf, you must add an identity mark of some sort to your golf ball before playing. These marks can come in different forms: dots, series of dots, your initials, or some elaborate designs.
Titleist golf ball markers also serve the purpose of creating identity marks or patterns on golf balls. It can also be used to draw lines on golf balls for easier and better alignment.