When you first begin training. You are given the rank of white belt or 10th Kyu (pronounced 'Q'). From here the rankings achieved will count down to 1st Kyu. This is the brown belt just before Black Belt or Shodan. This rank (Black Belt/Shodan) could also be called 1st degree black belt.
From here the ranking counts upwards From Shodan or 1st Degree to 10th Degree. You could also refer to these rankings as Dan's. 1st Dan to 10th Dan. Listed in numeric order; 1. Shodan 2.Nidan 3.Sandan 4.Yondan 5.Godan 6.Rokudan 7.Shichidan 8.Hachidan
Just a little note on ranking systems...
In the rooted past of many martial arts there really was no ranking system. You where either not so good and still learning, really good and still learning, older and wiser and still learning, or a fool and knew it all. The belt was what held your pants on, and kept your shirt tucked in.
Belt Colors. How they came to be what they are.
This was a story once told to me. Chose to believe it or not. I will pass it along all the same as no more than a 'Tale told me, I'll now tell you.'
All belts started out white as dye was expensive and, unless for show, an unnecessary waist of time. As one went through their life and aged the belt of course would age with them. Being a part of daily attire.
Presumably as the person aged they would become wiser and more experienced. Their belt of course becoming stained would darken as the years past. The harder that person worked the quicker the belt would darken. The belt would progressively get darker until it was black. As a white belt is commonly associated with a beginner or one less experienced as is a black belt associated with one who has more wisdom and experience.