Beyond the obvious - athletes with paraplegia, missing limbs and visual impairments - one of the biggest differences between the Winter Olympics and the Paralympics is that there is no judged sport in the latter.

It's just slightly modified hockey and curling games.

With competition set to get underway Saturday, here is a capsule look at the Paralympic sports.

PARA-ALPINE

The Paralympics used to hand out medals for every classification in three general disability types: standing, sitting and visually impaired. There are 11 classes alone for standing skiers depending on whether the athlete has cerebral palsy or is missing one limb or two and whether the amputation is below or above the knee or below or above the elbow.

Now, all standing athletes compete for one set of medals.

To ensure fair competition, a factoring system is used that assigns a percentage to all 11 classes based on the degree of the athlete's impairment. That number is multiplied by the skier's finish time to create an adjusted time that is used to award medals.

The factoring system is also in place for the sit-ski category, which has five classes based on functional trunk mobility, and the visually-impaired category, which has three classes based on the athlete's level of visual acuity. The visually impaired athletes ski 15-20 metres behind a sighted guide. The two communicate through helmet microphones and headsets. All three disability groups compete in the same five disciplines as able-bodied athletes - downhill, Super G, super combined, giant slalom and slalom - and on the same hill as the Olympians.

PARA-NORDIC

Cross-country skiing athletes also compete in sitting, standing and visually impaired classes. A percentage factoring system similar to that for para-alpine is used to enable athletes with different impairments to compete for one set of medals. There are 20 medal events, nine for men, nine for women and two relay races, the 4 x 2.5 kilometre mixed relay and the 4 x 2.5 kilometre open relay. Sprint races cover one kilometre, middle distance races are 5K for women and 10K for men and long-distance races range from 12K to 20K depending on gender and the three disability classes.

PARA-BIATHLON

The men compete at distances of 7.5K, 12.5K and 15K in all three disability classes. The women race at distances of 6K, 10K and 12.5K.

Visually impaired athletes shoot with the help of an infrared signal that is converted into an acoustic signal. The closer the barrel of the rifle aims at the bull's eye, the higher the pitch of the signal.

PARA-SNOWBOARD

The sport makes its Paralympic debut at Sochi as a modified snowboard cross event. Athletes get three runs down a course with different terrain features, including banked turns, rollers and jumps.

Their two best runs are combined to determine the final order. There is no factoring system as yet for para-snowboard athletes.

WHEELCHAIR CURLING

Basically the same sport as able-bodied curling, except there is no sweeping and games are contested over eight ends, not 10. And each rink must be a mix of men and women. Athletes deliver the stones, either directly by hand or through a quick-release extender cue stick, while their wheelchair is held stationary by a teammate.

SLEDGE HOCKEY

The sport is open to athletes with a lower bdy impairment - leg amputees or those with paraplegia, spina bifida or other muscle weakness - and the game is surprisingly fast and physical.

Players sit in a bucketstyle sled that is affixed to skate blades and they propel themselves across the ice by using the tiny picks on the end of short hockey sticks they hold in both hands.

Teams can dress just 15 players and periods are only 15 minutes, but most other rules - offside, icing, penalties - are similar to ablebodied hockey.