Rolex Daytona is both a Chronograph and Chronometer

Launched in 1963, the Rolex Daytona contains the Chronograph features such as the stopwatch functionality typically used in the racing industries.  Modern Daytona Chronographs have three additional subdials (also called registers) on the face of the timepiece.  These subdials are controlled by the two pushers on the right side of the watch, above and below the winding crown.  These pushers allow the racecar driver to accurately time the speed attained during a lap and the amount of time it takes to travel the whole course.  This can also be used in other active sports.

Rolex often rebrands certain things, as they have done in the photo above.  Instead of their Daytona, only being a chronograph, Rolex dubbed it a "Cosmograph."  Certainly there is a marketing element to it.  However, since the Daytona is both a Chronograph and a superlative Chronometer, I would say that the excitement leading to giving their Daytona a new nickname, is well deserved.