Junior skate sizes are for children between the ages of about 10 and 14. This is a large age range, so the sizes vary by manufacturer. Skate sizes are not based on age alone; factors like height, weight, and shoe size all affect which size you need.
Junior skates are usually smaller and have a narrower fit and are designed for a younger audience whereas intermediate skates offer a more adult-sized spacious feel and better power.
Skate size is generally expressed as the length of your foot, in inches. It means that, generally speaking, your hockey skate size will be about 1 - 1.5 sizes smaller than your shoe size (US) for men and 2.5 - 3 sizes smaller for women.
Fit 2 is the most popular size among Bauer's 3D Fit System and roughly corresponds to a regular width foot profile. It offers a standard heel depth, medium instep height, medium ankle wrap and medium forefoot width that is very similar to the current Supreme D-width fit profile.