English Jack Russell Terriers come in three (3) different coat types:
Smooth coat - short hair of all one length, hugging close to the body of varying thickness.
Broken coat - a mixture of smooth and rough, where there are 2 distinct layers, a short under layer with wispy long “guard hairs”, which are considerably longer and add a more fluffy look.
Rough coat - longer hair of all one length, can be soft to coarse in texture.
While all coat types will shed, and Jack Russell terriers are by no means a hypoallergenic dog, rough coats will shed a bit less than smooth and broken coats.