What is the proper term for a vertical line on a visualization that follows a mouse cursor?
Nb, screenshots have removed my mouse cursor but it exists on the same vertical plane as the dot in the second figure in both visualizations.
What is the name of a point on a visualization that follows a mouse cursor?
Both are supplementary mouse cursors, but do they have a canonical name?
Please tell me if these questions should be split into two or better suited for a different SE site.