A "fracture" is the technical term for a "broken bone," which is a crack in the bone. In fact, the two terms can be used interchangeably.
Bones break, or fracture, in two settings: with a significant amount of force, (as in the case of a twisting injury when the ankle bones fracture or a car accident when bones in the foot may break), or when a small or moderate amount of force is applied over and over again to a specific bone. The first type is also called a "traumatic fracture," while the second type is called a "stress fracture." Most commonly, the bone breaks but does not shift position (i.e. does not "displace").