To understand the difference between the Norfolk and Norwich Terriers, it is important to know the breeds history. It started in the second half od 19th century in English area called East Anglia, where local huntsmen developed a new breed by crossing several other breeds, most likely other terrier breeds like Glen of Imaal, Cairn, Irish and Dandie Dinmont Terrier and some local small red terriers.
This newly developed breed, thanks to its short legs, long body, strong prey drive, intelligence and indepence, quick reflexes and agile body, quickly gain a good reputation as a ratter and small game hunter. For most of the time, these dogs were known as Norwich Terriers, but also as Cantab Terriers, Trumpington Terriers or Jones Terriers.
The breed was finally recognized in 1932, when the first breed standard was written. The breed standard recognized two varieties of Norwich Terriers, one was pricked eared and the second was dropped eared. Later, in 1964, the dropped eared variety was separated from the Norwich Terrier and gained a name Norfolk Terrier.
So yes, the only big difference between these two breeds is the ear type. The Norfolk Terrier must always have folded ears, while the Norwich Terriers ears must be erected. The ears make it quite easy to recognize these two breeds apart, but there are some other small diferences between these two breeds.
One of the differences would be the eyes. Majority of Norfolk Terriers have smaller eye rims and Norwich Terriers look like they use black eye liner! Also, The Norwich may have a slightly harder coat, while the Norfolk has slightly larger feet, but those differences are very very small and it is almost impossible to spot them.
The last appearance difference might be the size, but again, the difference is very small. The breed standard for both breeds say, that the dogs should have weight between 10-12 lbs, which is 4,5 to 5,5 kg, but there is a difference in the height. While the Norwich Terrier height should be about 10 inches, which is 25cm, the height of Norfolk Terrier can be up to 12 inch, which is 30 cm.
The temperament of both dogs should be the same, as both were bred for the same purpose, in the area and in the same area. These dogs should have the typical spirited and independent personality of a terrier, but it is said, that they are softer than majority of terriers and thanks to that they make great loving family companions as well.
These dogs also tend to be quite alert and they know how to bark, which is why they can make good watchdogs, since they will alert you, when they will hear or see something suspicious. And of course, because of their history and higher prey drive, they are still amazing at hunting and chasing.
Of course, the temperament can vary a bit from one dog to another, but those two breeds should have very similar temperamental traits, and the only big difference between them are the ears. Once again, if you want to easily recognize these two dogs apart, just look at the ears. If you will see prick ears, than it is Norwich Terrier, if the dog will have folded ears, than you are looking at Norfolk Terrier.