What are the different type of coats of dogs?

Context: The coats of domestic dogs are of two varieties: "double" being familiar with dogs originating from colder climates, made up of a coarse guard hair and a soft down hair, or "single", with the topcoat only. Breeds may have an occasional "blaze", stripe, or "star" of white fur on their chest or underside. Premature graying can occur in dogs from as early as one year of age; this is associated with impulsive behaviors, anxiety behaviors, fear of noise, and fear of unfamiliar people or animals.

Answer: The coat of a dog varies depending on its breed. Typically a dog could have either a "double" coat or a "single" coat. "Double" coats are originated from breeds that live in colder climates. This type of coat consist of a coarse guard hair and a soft down hair. Dogs with "single" coat only has the topcoat.