There are about 900 breeds of sheep in the world.
The sit for exam is a modified version of the Stand for Exam. It is generally used in novice level classes and requires the handler to order the dog to sit and then to move away from the dog the length of the leash. The judge will then approach the dog and pet the dog's head.
A conformation dog show is not a comparison of one dog to another but a comparison of each dog to a judge's mental image of the ideal breed type as outlined in the individual breed's breed standard.