While related, the American Staffordshire Terrier and Pitbull were bred for different purposes originally.
AmStaffs tend to be slightly larger than Pitbulls on average. Male AmStaffs are 18-19 inches tall, females 17-18 inches.
Both have muscular builds but AmStaffs have broader heads and heavier bone structure. Pitbulls are more athletic looking.
AmStaffs are known for stability and friendliness. Pitbulls tend to be energetic with more stubbornness.
AmStaffs are prone to hip dysplasia. Pitbulls are more susceptible to skin allergies.
The American Staffordshire Terrier is recognized by the AKC. The Pitbull is not an AKC breed.
AmStaffs excel in conformation and obedience. Pitbulls are favored for athletic performance events.