Well, so are all dog breeds, until someone gives them a breed name. But Brittanys aren't really true Spaniels (here are the main spaniel varieties - more of 'em than you might have thought), which is why we call them plain Brittanys. They are more pointers, or setters, or something. A mix of various random things that happened to come together well.
Who cares what you call them. In our neck of the woods, Brittanys are the best all-purpose dog for the field, and maybe the most popular gun dog. They point birds, they retrieve, they do not mind water retrieves; they are bundles of energy and affection, and they are easy to train - a cross look is usually enough to get your point across to these emotionally-sensitive critters. The larger American version can handle the large spaces.
But you need at least two of them. One Brittany isn't a fully happy dog. They need the exercise and the company they can give each other. Every hunter, or every human, can use a few sweet Brittanys around the place.
Here's a nice Brittany site.