Shadow
"Koryu" is generic or "umbrella" term for the classical Japanese fighting arts.
"Koryu" sort of means "old school." Or the schools that date back to the days of actual warfare and dueling.
(rough explaination)
You would find both katana AND bokken in many koryu schools.
A bokken is a wooden practice sword of the appox size and weight of a "real" blade.
Although dangerous in and of itself, its generally used in place of a katana for training purposes.
Some koryu use spears or staff or a wide range of other weapons.
Some also teach weaponless/empty hand skills.
The website listed is one that has information about MANY extent koryu schools, some information on what they teach and some even have some info on where they are taught.