At its core, is a bitmap/pixel font . Unlike standard TrueType or OpenType fonts (which use mathematical curves to define shapes), bitmap fonts are composed of a grid of pixels. When you type the letter "A" in 04b16b, the software literally places black squares on a specific grid pattern.
: At exactly 8px or 12px sizes, they remained perfectly sharp without any "anti-aliasing" (the grey fuzz around edges). 04b16b font