Breed Standards
The breed standard is a description or kind of blueprint for the breed drawn up by the Kennel Club. One of the aims of breeders should be trying to produce puppies that adhere to the standard in the closest way and at shows judges are assessing which animal closest complies with the standard. Standards can never be totally strict and judges usually have to make subjective judgement calls on which element is more important to them than another. There can be a valid difference of opinion here but in any breed the better quality dogs will win the most regularly as they will appeal to a higher percentage of judges.
Other Kennel Clubs may draw up their own version and there is the International dog organisation, the FCI, which most countries default to. These standards will vary slightly from each other and this means depending where in the world you are, the the breed standard varies slightly, below are the UK, World (FCI) and American breed standards.