You will come across lots of grades when looking for a brush. There is no industry standard. Even the same so called grade varies with different makers. So you have terms that include words like finest, silvertip, super, best, pure and combinations of these words. They are all to do with the part of the badger they came from as well as treatments applied to the hairs.
There is a mass of information about shaving brushes on the shaving forums. Here is one which describes the grades of several of the famous makers and brands.
This is a term used to describe the number of bands of colours visible above the brush handle. Usually it's three: light, dark, light. But in recent times, particularly for short loft brushes, you come across two band brushes. These are usually very dark from the base with almost white tips. These are mostly made from long best badger hair which is quite stiff yet very soft at the tips. It makes a fine all round brush suitable for use with both creams and hard soaps.
Some boar brushes have hairs that are all one colour - a one band?!
Badger Grades explained - Badger and Blade Wiki