A fracture is any loss of continuity of bone. Anytime the bone loses integrity — whether that's a hairline crack or the shattering of bone into a dozen pieces — it's considered a fracture. A broken bone is a fractured bone, and vice versa.
If you had a crack in your car windshield and I asked how long it had been broken, would you correct me? Would you say it's not broken, it's just a fracture? Probably not. In fact, you'd probably tell me about the rock that did the deed on the freeway. Most of the time, we all use the terms fracture and break interchangeably. It's the same in the medical field.
On the other hand, there is a difference between a sprain and a fracture, but you might not be able to tell without an x-ray.