They have two ranges: the CLP and the CVP ranges. The CLP, or Classical range, focuses on emulating a traditional acoustic piano whereas the CVP, or Versatile range, offers a much wider choice of voices and percussion accompaniment options. The most recent CVP models can have hundreds of voices and are typically much more expensive than the CLP range.
Yamaha has a dedicated website to their Clavinova range which allows you to compare the features of the various models. This can be very useful when researching and discovering your options before walking into the local music showroom.
You can view by following this link: http://clavinova.yamaha-europe.com/uk/index2.html