Cross-country bikes (abbreviated to XC) are all about covering ground quickly, whether it’s in a race or just on a big day out in the mountains.
For racing use, hardtails are still preferred by many, but lightweight full-suspension designs are becoming more popular. They tend to have around 80 to 120mm of travel at the front, usually equipped with a lockout switch that helps prevent the suspension sapping pedalling energy on smoother sections of trail and longer climbs.
Cross-country bikes tend to use larger-diameter 29in wheels, combined with lightly treaded, low-volume and fast-rolling tyres for maximum speed.
XC mountain bikes are the lightest on the trail. They give you the ultimate performance edge, so you can go as fast as your legs and heart will allow, and come back grinning. Trail bikes are your do everything bike. They're versatile, light, and exceedingly capable, climbing as well as they descend.