Acid and base in terms of these ions

What is a base and an acid in terms of their relative H+ and OH- ion concentrations?
Also, what does it mean for a solution to be neutral in the terms of these ions?

I'm crummy at chemistry, so any help, even if you post a website link, is very much appreciated.

Try this link ----> http://lrs.ed.uiuc.edu/students/erlinger/water/background/ph.html

For your first question

And to the second one;

For a solution to be neutral, it will have no charge, not an acid or a base. Like water, H2O