Bitmap font

A bitmap font is simply a set of pre-rendered glyphs in a grid, often packed into a sprite sheet together with a table of where each character sits and how wide it is. Drawing text becomes copying out the right cell per character — cheap and predictable, which made it the standard in terminals, early GUIs and games.

The price is resolution: a bitmap font looks crisp only at the size it was drawn, and scales up jagged. Outline fonts like TrueType solved scaling, and signed distance fields gave games back sharp, scalable text from a single small texture. In games the glyphs are often drawn as hardware sprites or via an atlas lookup.