- Typeface
- The design of a set of letterforms (e.g. Helvetica). A typeface family includes all weights, styles, and widths of that design.
- Font
- A specific instance of a typeface — e.g. Helvetica Bold 16pt is a font; Helvetica is the typeface family.
- Serif
- Typefaces with small projecting features (serifs) at the ends of strokes. Often associated with editorial and academic settings.
- Sans-serif
- Typefaces without serifs. Generally cleaner on screen at small sizes; common for UI and modern marketing.
- x-height
- The height of lowercase letters (specifically 'x'), excluding ascenders and descenders. Higher x-heights generally read better on screen.
- Variable font
- A single font file containing multiple weights, widths, or styles along continuous axes. Smaller download than multiple static fonts.
- Pairing
- Two or more typefaces used together in a design. Successful pairings balance contrast (serif/sans, display/body) with harmony (similar x-height, mood).
- @import / @font-face
- CSS rules to load external fonts. @import links to a hosted CSS file (e.g. Google Fonts URL); @font-face declares a custom font from your own files.