How does Gears works on a cycle?

The way gears work is that they change the ratio between cadence (how fast you pedal) and how fast the wheel rotates. Lower gears help you pedal easier, while higher gears help you pedal faster.

Why are gear cycles more popular than single-speed cycles?

Gear cycles offer versatility, making them suitable for different terrains and fitness levels. They allow cyclists to optimize their pedalling effort in different conditions.