Try Prime for free. Prime free trial and invitee customers: We will automatically apply an Amazon.com Gift Card to your Gift Card Balance in the amount equal to the Prime exclusive discount after you become a paid Prime member.
The vertical line is known as the y axis. It is nothing more than a measuring stick to count how far up or down a point is from the horizontal line. The horizontal line, then, is known as the x axis and measures the distance left or right from the vertical line.
In x-y plots, like the one above, the x-axis runs horizontally (flat). Typically, the x-axis has numbers representing different time periods or names of things being measured. In this plot, the x-axis measures the amount of money spent by a country on elementary and secondary education per child.