Bike gears or speeds allow you to pedal more efficienttly. \n\nThe number of speeds your new bike has is the result of your front gears multiplied by the rear one. Newer MTB bikes will range from 21 to 27 (3 on front and 7,8 or 9 on the rear cog) while road bikes will range from 14 - 18 (2 on front 7,8 or 9 on the rear cog)\n\nThe front gears are controled by your left hand shifter (dial/knob) the smaller ring is easier for the hills, while the big ring is better for building speed or going downhill.\n\nThe rear gears are controlled by your right hand and they work the opposite as the ones on front, the bigger cog will be easier going uphill and the smaller cog will be harder.\n\nMost of the time you can ride on the middle ring, while shifting only the rear cogs. As you get the hang of it, start shifting the front rings.\n\nI leave some links that are more technical and will help you enjoy your new bike