When you pass a grading, you progress to the next level and will be given a new belt to reflect your new level. For example, when you pass your first grading you will be awarded a Yellow Tag belt. You will also be given a certificate as proof of your new grade. Both the belt and certificate are given to you FREE (so long as you pass of course).
Each of the main belt colors has a meaning (excluding Tags: these are half-way points between the main belts). Progression through the belts tells a story of the student developing from seed through sapling to tree.
(beginners) - The origin or beginner
8th KUP - The earth, soil or seed
6th KUP - The growth or grass
4th KUP - Reaching for the skies
2nd KUP - The flow of blood or danger - the student has all of the technique of a black belt but needs to learn control
1st Degree - Impervious to darkness and fear