Some More Terms Used in Font DesignFont • A set of typestyles designed to work together.
Typeface • Classification of type into Serif, Sans-serif, Script, Black-letter, Decorative, Brush Script, etc.
Typestyle • Regular, Bold, Italic, Bold Italic, SMALL CAPITALS, Outline, etc.
Character • A letter, symbol, or accent that is assigned a code-point so that it can be typed.
Code-point • A unique number assigned to a character.
Glyph • A graphical outline or letter form.
Contour • A closed curve of one or more that makes up a glyph.
Nodes • Points that define the curves that make a contour. Nodes may be on-curve or off-curve.
Composite Glyph • A glyph composed of two or more other glyphs. A base letter like a, for example, is often combined with an accent or diacritic like ¨ diaeresis) to form a composite glyph like ä (a diaeresis)
Composite Glyph Member • One of the glyphs used by a composite glyph or by several composite glyphs. Some composite glyph members may be characters in their own right, or they may simply be included in a font for composing composite glyphs.
Offset • The distance that a composite glyph member is offset vertically or horizontally when used in a composite glyph.
Diacritic • An accent
F-unit • The smallest unit used in font design. Many fonts are designed at 2,048 funits/em.
Em-square • The square within which most letters are designed to fit. Script letter forms or combining diacritical marks may overlap the em-square.

• The arm of the T overlaps the em-square to the right, and the bottom of the italic ƒ overlaps the em-square to the left.
• Four
nodes are selected — two
on-curve, and two
off-curve nodes.• The blue grid is set at 1024
f-units so four small squares make one
em-square.
• The
composite glyph ä (a diaeresis, code-point 228) is composed of the
glyph of the
character a (code-point 97) and the
diacritic ¨ (diaeresis, code-point 168).
• The
right side-bearing of the italic ƒ is shown as a dotted line.
• The capital
T sits neatly on the
baseline, while the
descender of the italic ƒ descends almost to the
Win-Descent line.
• The space above the glyphs to the
Win-Ascent will be occupied by
diacritics of capital letters like Ä (A diaeresis, code-point 196).