What are the marks or divisions on the edge of a ruler commonly referred to as?

The term "graduations" refers specifically to the marks or divisions on the edge of a ruler that indicate various measurement increments, such as inches or centimeters. These marks help users accurately determine lengths and distances by providing a visual guide for measurement. Each graduation represents a specific unit of measurement, allowing for precise reading of dimensions.

In contrast, "grids" usually refer to a network of horizontal and vertical lines that create a pattern for layout or positioning rather than measurement. "Measurements" is a broader term that encompasses the act of determining dimensions or quantities, while "lines" is too vague and could refer to any line without the specific context of measurement. Therefore, "graduations" is the most accurate term for the marks you find on a ruler.