Typography Glossary
55 terms defined — from letter anatomy and spacing metrics to web CSS properties and typesetting practice.
A
B
Baseline
The invisible line upon which most letters sit; the reference line for vertical alignment and rhythm in typography.
Baseline Grid
An underlying grid of horizontal lines spaced at regular intervals to align baselines of text across columns and components.
Bowl
The curved stroke that encloses the counter of a letter, as in b, d, o, or p.
C
Cap Height
The height of capital letters measured from the baseline to the top of flat capitals like H or E.
Clamp
A CSS function that clamps a value between a minimum and maximum, widely used for fluid typography: clamp(min, preferred, max).
Contrast Ratio
The luminance difference between text and background colors; WCAG AA requires 4.5:1 for normal text and 3:1 for large text.
Counter
The enclosed or partially enclosed white space inside a letterform, such as the hole in o, e, or a.
Crossbar
A horizontal stroke connecting two stems, as in H, A, or the bar of a lowercase e.
D
E
F
Fluid Typography
Typography that scales smoothly between minimum and maximum sizes across viewport widths using clamp(), calc(), or vw units.
Font
A specific weight, width, and style instance of a typeface, such as Helvetica Bold 12pt or Inter Regular.
Font Family
The CSS property that specifies a prioritized list of typefaces to render text, with generic fallbacks like serif or sans-serif.
Font Loading
Strategies for delivering web fonts efficiently using @font-face, font-display, preload, and fallback metrics to minimize layout shift.
Font Pairing
The practice of combining two or more typefaces that contrast yet complement each other for headings, body, and UI.
Font Size
The CSS property that sets the size of text, typically in rem, px, or em; body text on the web should be at least 16px.
Font Style
The CSS property for italic or oblique variants of a typeface, distinct from weight and width.
Font Weight
The thickness of letter strokes, expressed numerically (100–900) or with names like Regular (400) and Bold (700).
H
K
L
Leading
The vertical space between lines of type, traditionally measured from baseline to baseline; in CSS this is controlled by line-height.
Letter Spacing
The CSS property that controls spacing between characters; the web equivalent of typographic tracking.
Ligature
Two or more letters combined into a single glyph for better spacing or aesthetics, such as fi or fl.
Line Height
The CSS property that sets the height of a line box, controlling vertical spacing between lines of text.
M
Measure
The width of a block of text, usually expressed in characters per line; also called line length.
Modular Scale
A sequence of sizes built by multiplying a base value by a fixed ratio, commonly used for typography and spacing.
Monospace
A typeface where every character occupies the same horizontal width, used for code and tabular data.
O
P
R
Rag
The uneven edge of left-aligned or right-aligned text; good rag avoids holes and ladders that distract the reader.
Readability
How easily a reader can understand written text, influenced by measure, line height, contrast, and typeface choice.
Rem
A CSS unit relative to the root element font size; 1rem equals the html font-size, typically 16px.
S
Sans Serif
A typeface without serifs at stroke endings; commonly used for UI, screens, and modern editorial design.
Serif
A small stroke or foot attached to the end of a main letter stroke; typefaces with these features are called serif typefaces.
Small Caps
Capital letters sized to match the x-height of lowercase text, used for emphasis, abbreviations, and elegant hierarchy.
Spine
The main curved stroke of the letter S, running from top to bottom.
Stem
The main vertical stroke of a letter, such as the primary vertical line in l, b, or d.
T
Terminal
The end of a stroke that does not include a serif, often found in sans-serif or script letterforms.
Tracking
Uniform adjustment of letter spacing across a range of text, affecting overall density and readability.
Type Scale
A set of font sizes derived from a base size multiplied by a consistent ratio to create harmonious hierarchy.
Typeface
A designed family of letterforms sharing a common visual style, such as Helvetica or Georgia.
Typesetting
The process of arranging and formatting text for publication, including font choice, spacing, hyphenation, and alignment.
Typography
The art and technique of arranging type to make written language legible, readable, and visually appealing.
Typography Hierarchy
The visual ordering of text elements by size, weight, spacing, and color so readers understand structure and importance.
Typography Tokens
Named design variables for font families, sizes, weights, and spacing that create a single source of truth across products.
V
Variable Fonts
Font files that store a range of design variations (weight, width, slant) in a single file, controllable via CSS axes.
Vertical Rhythm
A consistent vertical spacing system, often based on a baseline grid, that aligns text and UI elements across a layout.
Viewport Units
CSS units based on viewport dimensions (vw, vh, vmin, vmax), often used inside fluid type calculations.