Letterforms can be thought of as the black ink that you see here. But by creating this foreground, you’re also creating a background. The white of the page becomes its own shape. Given an o you not only create a circle of black – but also a white circle within. These negative spaces are called “counters.” They are counter to the letter forms themselves. This little area inside the e is a counter too. An o is completely closed, but in other letters such as this u, the counter is open. So the e has a closed counter (even more specifically called the “eye”) – but it also has an open counter in its little loop.