To make things a bit more confusing … even within the same breed, there can be big differences!
About a century ago, when most dogs were working dogs, there was mostly one type of each breed – the working type.
As dog ownership became more common and the American Kennel Club (and its cousins in other countries, such as the CKC in Canada) determined breed standards and started to encourage breeding dogs to fit this (visual) standard, we could see quite some deviation in the types of dogs.
The dogs that were still bred to work and perform their original function are the “working lines”, and the dogs that were mostly bred to fit the breed standard and attend dog shows are the “show lines”. Dogs that are pet dogs are usually from show lines, and might just be called “pet lines” if they were bred to be family dogs and companions.
In some breeds, the difference between the different lines can be big! Here for example are Golden Retrievers:
The different lines can vary in:
and of course: their temperament!
You will find working-bred dogs to have a lot stronger instincts and are usually more high-strung. As you look through the lessons, consider that: the closer to his original purpose your dog was bred, the more of it is still in him!
A working line Border Collie is likely quite a bit more motion-sensitive than a show line one, for example. If you got a Border Collie puppy from a sheep farm, and your friend got one from a breeder that shows her dogs in conformation, chances are that yours will be more intensive than the other.
You see: even within a breed there are differences.