You have little or no experience in riding a mountain bike but you can ride mostly on gravel tracks or smooth trails. You have a modest degree of basic fitness from exercising once or twice per week. You can ride on flat or gently rolling terrain at a steady pace for 2 to 4 hours per ride.
You can ride on gravel tracks and trails with confidence, taking loose stones and rough ground in stride. You may have some experience riding man-made single trails or rough gravel roads. You are moderately fit from two or three sessions of exercise per week. You can ride hilly terrain at a steady pace, or do shorter rides in more demanding terrain.
You can tackle most normal terrain including steep, rough and narrow tracks with exposed tree roots and other small obstacles as part of a normal ride. You can ride most small drops/step-downs or similar technical trail features. You have good fitness from regular exercise and active involvement in cycling. You can ride full days in any terrain at a steady pace.
You can ride over just about anything, including very rocky and steep descents including drop-offs over two feed and other even more challenging trail features. You have excellent fitness from regular training and a large amount of time riding or even racing. You can ride anywhere at a demanding pace.