The wrist has several definitions, but generally, when one refers to a wrist fracture, they are referring to the end of the radius (also referred to as the distal radius). It is one of the bones in the forearm and is the most commonly broken bone of the wrist. However, the wrist can also technically include the other forearm bone, the ulna, as well as the eight small bones in the hand.
A break and a fracture are the same. It is the pattern of the fracture that determines the severity of it.
Simple fractures refer to ones where there may be 1 or 2 large bone pieces that are well aligned and stable. Hairline fractures fall into this category.
Displaced fractures refer to ones that are crooked. Sometimes the crooked fractures can be reduced, meaning they can be pushed back into place. After this is done, you are placed in a cast to hold the position. However, the fracture can be unstable, meaning that even in a cast, they may shift and become crooked again. Not all crooked fractures need surgery though. Some amount of crookedness on x-rays may not translate to any functional deficit in your activities of daily living.
Intra-articular fractures refer to fractures that go into the wrist joint. Sometimes there is just a crack in the joint, but sometimes it can become wide or it can shift so the joint becomes uneven. These types of fractures are harder to reduce and oftentimes need surgery. Also, the more uneven the joint is, the greater risk you have for developing arthritis in your wrist at a later time. This could cause pain.
Comminuted fractures refer to ones that have many many pieces. Comminuted fractures may be intra-articular and displaced as well, so these are very severe fractures.
Not all wrist fractures need surgery. Treatment is dependent on many factors, not just the xray. Factors such as age, activity level, hobbies, occupation, hand dominance, prior injuries or wrist arthritis, and other medical problems are very important when considering treatment and should come up in discussion with your surgeon.