Answer:
Y-Axis
Step-by-step explanation:
The vertical line on the side of a graph is called the y-axis. The y-axis is used to represent the dependent variable in a graph, while the horizontal line (side-to-side) is called the x-axis, which represents the independent variable. Together, the x-axis and y-axis create a coordinate system that allows data points to be plotted and relationships between variables to be visually represented.