Final answer:
A descriptive name for a part of a chart or axis in mathematics is called a label, such as 'x-axis' for the horizontal axis and 'y-axis' for the vertical axis, with specific labels providing clarity on the data type.
Step-by-step explanation:
The descriptive name that identifies a part of a chart or the axis in mathematics is typically referred to as a label. In graphs or charts, the horizontal axis is usually called the x-axis and the vertical axis is known as the y-axis. Each axis will have a label that usually describes the type of data being represented.
For example, if you’re plotting a graph of daily temperatures over a week, the x-axis might be labeled 'Days of the Week' and the y-axis might be labeled 'Temperature in Celsius'. The axis labels help anyone reading the chart to understand what the data points represent and make the data easier to interpret.