Measure Result in Mechanism

I'm using Mechanism Feature to analyze a position of pin joint that is driven by a slider moving at a constant speed of 2 mm/s over a duration of 6 seco

 However, I'm having trouble understanding the graph when I select the "Measure vs Measure" option. The X-axis represents the joint's rotation in degrees, which makes sense. But I'm unsure what the Y-axis represents.

Could someone please explain what the Y-axis measure might indicate in this context? or maybe explain whats the objective of Measure vs measure graph type.