There are about 900 breeds of sheep in the world.
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.
A specialty show may be regional or national. A "Best in Show" win at a national specialty show is tremendously prestigious, indicating that the winning dog or bitch triumphed at a contest which attracted entries from the most serious fanciers of that breed in the country or continent. Some specialty shows attract international entries.