What is the second variable in the plot found in Field Summary tool?

[georgeliu1998]

I was trying to better understand the variables using the Field Summary tool. After connecting a Browse tool to the R output of the tool, I can see the report which includes scatterplots for all variables. So my question is, what is the second variable used here in the plot, other than the variable itself? Thanks in advance!

 

[Joe_Mako · Accepted solution]

The x axis is the sequence of the records, from first to last is arranged from left to right in the chart.

[georgeliu1998]

Thank you @Joe_Mako!