I was in it all through my childhood until graduating high school.
It's a program where kids sign up for different projects, and are then judged on them. Everyone recieves a color of ribbon based upon their performance or product. The Grand Champion and Reserve Grand Champion usually get trophies and a rosette.
You can show farm animals, dogs, cats, rabbits, chickens, etc.
You can also sign up for arts and crafts, sewing, photography, baking, horticulture, entemology, geology and the list goes on.
It can be good for children or a waste of time for parents. Some parents do their children's projects for them, other children work on their projects independently all year long, giving them a sense of reward and accomplishment at the end.