Cyclocross also know as CX, CycloX or cross is predominately a winter season sport and is a relatively new cycling discipline to the UK. A bit like cross country for mountain bikes it usually is held at a venue with multiple terrains, including on and off road section and is done in laps. There are usually different races for all ages of riders, so you get fair times according to category. It is a really big sport in Benelux and the USA who have been doing it for ever more. The big different between it and cross country mountain biking is the bike itself. Even XC MTB bikes are heavy, the beauty of cyclocross is that the bike looks like a road bike and weighs much less, with the added features of knobbly tyres for grip and disc brakes as the bike rims get wet and muddy. The clearance is also larger on a cyclocross frame to allow for mud build up.