The American Kennel Club (AKC) recognizes only the Groenendael under the name "Belgian Shepherd", but also recognizes the Tervueren (with the alternative spelling "Tervuren") and the Malinois as individual breeds. The Laekenois can be registered as part of the AKC foundation stock service and should eventually be recognized fully by the AKC.
The Australian National Kennel Council, the Kennel Club (UK) and the New Zealand Kennel Club recognize all four as separate breeds. The Canadian Kennel Club follows the FCI classification scheme and recognizes all four as varieties of the same breed.
All four breeds are hard-working, intelligent dogs of the same general size and temperament. They differ mostly in their coats and superficial appearance. The Malinois is often mistaken for a German Shepherd Dog.
They are so closely related that, when breeding any two dogs of the same "breed", it is possible for puppies of different "breeds" to be in the same litter. For example, a Groenendale litter could contain a brown-coated long-haired puppy; in countries that consider them the same breed, this is fine and the puppy would be a valid Tervueren, but AKC considers it to be an aberration of the all-black Belgian Shepherd and disqualifies it. Likewise, a Tervueren could have a short-coated puppy; in some countries, this is merely a Malinois coat variation but the AKC again considers it to be an invalid aberration.
All the Belgian Shepherd breeds need a lot of activity and close interaction with people. Like most herding breeds, they need a job to do (be it frisbee in the park, herding, learning tricks, dog agility). Throwing a toy endlessly for the dog to fetch works to tire out some breeds, but the Belgian breeds become easily bored with such simple repetition. They are intelligent dogs who can easily become bored. They can also behave as if they think that they are smarter than their owners, so it is important for the owner to know how to train dogs or to enroll in training classes.