I do not know if my arm is sprained or fractured?

See a doctor: You will need at least an x-ray to tell if there is a fracture.

A true sprain is a: ligament injury and can be as significant as a fracture for late effects, needing care just like a fracture does! Too often we use the word sprain to mean negative X-rays or no fracture. So first recognize that a sprain needs treatment too. Now if the question is do you have something like a bad bruise that will just get better vs a sprain, fracture or other injury that needs treatment.

Have it checked out: The old saying " if I can move it, it must not be broken" is not true. Fractures usually hurt more than sprains, but everyone's pain tolerance is different. If the pain is significant and it hurts to move the area or touch the region, then it should be checked by a physician, either an urgent care center or an ER doc.

Fractures: have significant pain, deformity and loss of function. Strains are sore, you can have bruising and the arm can be stiff. If it is a fx the arm can be stabilized by a splint or Cast initially. An X-ray can confirm if there is a fracture and permanent treatment can be either casting, splinting or surgery depending on the fracture. Sprains are treated with rest, ICE and Nsaids.