Difference Between Adult And Junior Boots Ski Binding Adult/junior Help?

Ski binding adult/junior help? - difference between adult and junior boots

I recently went to buy new bikes and have a pair of boots. The seller said that he (connections with the boots of the young adults a lot of this guy was really full of them did). Is that true? and what is the difference between the adult and links to the juniors? As you can tell the difference?