
At all Championship shows there will be a certain number of classes for each breed and they will in most cases be seperated into dogs and bitches (not always for small breeds)
So depending on the numerical strength of the breed an average line up could be -
Puppy Dog, Junior dog, Yearling dog (which are all age restricted classes )
Post Graduate dog, Limit dog, and Open dog ( which are all classes that are restriced by how much a dog has achieved, Open being for the most successful dogs and Champions)
Then there would be the same classes for bitches. This is just an example of what the classification could be there could be more or less classes but the details would be in the schedule for entering the show.
Once the judge has judged all the dog classes their will be the challenge. All the class winners are called back into the ring and the winner is then the best Dog or when CC's are on offer then they are the CC winner. The judge will then pick the second best dog from the class winners and also will call back into the ring the dog that got 2nd place in its class behind the one just awarded the CC to pick the Reserve CC winner.
This will be repeated for the Bitches so there will be a Dog CC winner and a Bitch CC winner who will then be judged for which will take the Best of Breed.
Just to make things a little more complecated there are some breeds that will only have one CC available at certain shows to cover both dogs and bitches and that CC will be awarded to the Best of Breed.
Its a kind of knockout competition really.
All that is probably as clear as mud :-D