Understanding Horizontal and Vertical Components in Moving Charges

[stmartin]

http://www.cco.caltech.edu/~phys1/java/phys1/MovingCharge/MovingCharge.html
"As time goes on, the line becomes more and more perpendicular, the horizontal component increasing faster than the vertical component"
Which is that horizontal and which vertical component?
Please help me. Thank you.

 

[malawi_glenn]

horizontal is parallel to the horizon ________________

Vertical is perpendicular to the horizontal

 

[stmartin]

horizontal is parallel to the horizon ________________

Vertical is perpendicular to the horizontal

And what this means? "As time goes on, the line becomes more and more perpendicular, the horizontal component increasing faster than the vertical component." What the author want to say?