If it's called "free" climbing, why do climbers use gear to climb?

Free climbing refers to a form of rock climbing in which the climber ascends without the use of gear to aid progression. It is a common misunderstanding that free climbing means climbing with no protective gear. Both sport and traditional climbing make use of protective gear to prevent injury and death, and are both considered free climbing. This is in contrast to free solo climbing, another form of free climbing in which the climber uses no protective gear.