Terriers such as this Airedale terrier in this video have coarse and wiry coats unlike many other breeds of dogs. We call them by an odd name “broken coated” terriers. I was given an explanation by my mentor that “broken” simply refers to the coarse wire coat, meaning not silky or smooth. Broken meant rough and coarse but over time the term also began to refer to a dog with a double coat of soft undercoat and rough, harsh wire guard hair.
If you are showing your terrier or if you care about such things as coat integrity, it becomes essential to groom these breeds correctly by pulling each hair out when they are dead, in order to preserve the correct texture and correct color of the coat. Terriers were designed and developed to work in harsh conditions in Britain. They are not passive palace lap dogs, they were designed to hunt and kill vermin and other animals like otters and rabbits in harsh weather and/or terrain, such as working in rain, in wind, on scraggly rocky cliffs, in dense thorny brush or go to ground with prey that sometimes fight back with claws or teeth. So their coats were developed to withstand such conditions. The benefit of this wiry guard coat includes weatherproofing.
To preserve the integrity of this coat, we try our best to avoid cutting the hairs or shaving/clipping it.