What is the difference between chocolate makers and chocolatiers?

First of all, these professions need two very different knowledge and skill sets.

Chocolate makers manufacture chocolate from dried cacao beans using specific equipment such as a roaster, grinder, refiner mill, conch and tempering machine. Their finished product is pure chocolate – usually in bar form.

Chocolatiers source and blend that pure chocolate, made by the chocolate maker(s), for specific properties and flavor profiles from which to develop recipes for their own unique bonbons, confections and bars.

The same is true in other food industries – a baker doesn't own a flour mill from which to produce flour to make her products. It's the miller who buys wheat grain which he mills into flour. The baker then buys flour from the mill to make her cakes. The mill and the baker are two different kinds of businesses, but partners in the process of turning grain into flour and then into cakes and cookies.