What are the practical differences between 700c32 tires and 26-inchers? I know that 26 inch tires are mountain bike tires - there are a wide variety of tires/treads that are available and they can be used for everything from pavement to technical mountain trails.

My assumption on 700c32 is that they are basically just larger versions of the 700c28 tires on my Trek - fewer tire choices available and are limited to pavement. Is this a correct assumption?