Bannock is a generic description of flat breads cooked in Scotland, Ireland and the north of England - i.e. all those regions where wheat was not the primary staple grain. The grain used in bannocks might differ, just as it does in loaves of bread, but the common factor was that they were cooked on a griddle and were unleavened.
They are very delicious. Not as enriched as girdle or drop scones, certainly not as sweet, but they make a wonderful tea bread nonetheless. In this recipe,