Bouldering is not going out for the evening in Bouder, Colorado. It is the act of climbing compact surfaces with interesting characteristics. Often, this means a boulder, which is where it gets its name. 10 to 15 foot walls are also popular.
The goal of climbing is to get from one point to another. Most climbs have set routes. The cool thing about bouldering is it does not. You can create all kinds of different routes across a boulder to keep things interesting and test yourself.
More and more people view bouldering as less of a training session for rock climbing and more of a sport in and of itself. A single unique boulder can present you with literally years of challenges as you try different routes, holds and so on.
Bouldering is infinitely safer than climbing a chimney on a cliff face. That being said, it is not without risk. Fall at the wrong angle and you can break a lot of bones. To prevent this, throw down a pad under you climbing area.
The same goes for avoiding injuries. You will constantly see people just jump on a boulder route without warming up at all. This is a recipe for an injury. Your shoulder has to carry the same weight whether you are 8 feet in the air or eighty. Warm up!
An offshoot of bouldering is buildering. Walk by a fine dining establishment that serves adult beverages and has climbers as clientele and you will see a strange thing. There are people climbing various wall surfaces outside the establishment.
Buildering can be a good bit of fun, but is hardly high in the pantheon of safe climbing. The ground is usually brick, concrete or something hard. Falls can hurt. The local authorities also tend to take a dim view of the activity and arrests are common.
Everyone has their favorite form of climbing. For convenience, learning new techniques and setting your own routes, bouldering is pretty hard to beat.