Climbing can be done indoors out outdoors, usually as a pair but often as part of a group.
Indoor climbing involves following a series of coloured grips, with different colours corresponding to a different level of difficulty. Your climbing partner, called the belayer, controls the rope that stops you from falling and preventing an injury.
Bouldering is a form of rock climbing that doesn’t use ropes. Instead, you only climb a few metres off the ground with crash pads beneath you to cushion your fall.