Every time I see an adult on a bicycle, I no longer despair for the future of the human race. —H. G. Wells
Road bikes are designed so the rider can go fast and just enjoy riding. As opposed to mountain bikes, road bikes are much lighter so you may not want to go biking down any mountains on this bike. Road bikes use different materials than mountain bikes and take into consideration the total weight to allow for optimal speed.
OK - You've picked out your bike - now it's time for a road trip!