Counter

A counter is an empty space within a letter that is generally completely closed off. Letters in our alphabet that possess them are the capital letters A, B which has two counters, D, O, P, Q, and R, and the lower-case letters a, b, d, e, g, o, p, and q. the counter of the lower-case e, the upper part, is also called an eye. In many cases the part of the letter that encloses the counter is called a bowl, as in the rounded shapes in both the capital and small forms of B/b and D/d,, with the exclusion of letters like A and e cyan.

An empty space that is not closed off, as in the letters n and v, is called an aperture otherwise known as an open counter. The small letters a (in it's double-story form) and e exhibit both a counter and an aperture. ABDOPQR abdegopq 04689