Much later, toward the end of the first milleneum A.D., Charlemagne's court standardized on a written form which included most of the features of our lower case alphabet. It has developed unabated ever since. Today it is also a science, with type designers concerned not only with the appearance of new fonts, but with their psychological impact on readers and with their incorporation into new and broadening fields of type reproduction. A few basic facts about typography are worth knowing. A font is a complete set of characters in one size and typeface.
Courier is one font.
The same set of characters in another size constitutes another font. Fonts are identified by their size, typeface family, weight and style. Point size is the approximate distance from the top of a font's tallest character to the bottom of its lowest character. Approximate because some fonts are designed to be taller. 12-point Times Roman.