Basically, there are three types of dance:
This is the one with two subtypes. The steps are the same for both; the difference is really only in the type of music used.
The most well-known type. The music is usually in 4/4 time, although 2/4 and 2/2 are also sometimes used.
At a similar speed to reels, but in compound triple time - usually 6/8 but 12/8 is sometimes used.
There's only one sort of these:
These have a special sort of footwork and movement of their own.