Taken from:What is a Cross Country?
The "jack of all trades" of mountain bikes; a cross country bike is what 80% of general rider population use. These bikes are able to tackle a variety of terrain that most novice and intermediate riders can handle. They are more efficient bikes because they are built for longer distance riding because they are lighter and have less suspension travel to enable better power transfer in each pedal stroke; therefore making it better for climbing. A large majority of these bikes are hard tailed to aid in the efficiency of every stroke; however, bikes companies are now manufacturing full suspension cross country bikes that are both excellent climbers and are more comfortable than hard tails in long distance rides by absorbing bumps on the back wheel.