A typeface or font refers to a set of images used to represent text on a graphical display\footnote{This terminology dates back to printing press technology}. 
In 1983, Donald Knuth published ``The METAFONT Book'' which described a vector approach to specifying fonts and a program for creating these fonts\footnote{knuth1983metafont}. Previously, only rasterised font images were popular; as can be seen from the zooming in Figure \ref{vector-vs-raster-scaled} this is problematic given the prevelance of textual information at different scales and on different resolution displays. 

Knuth used Bezier Cubic Splines as discussed in Section \ref{} to define ``pleasing'' curves in METAFONT, and this approach is still used in modern vector fonts. Since the paths used to render an individual character (often called ``glyphs'') are used far more commonly than general curves, document formats do not require such curves to be specified in situ, but allow for a choice between a number of internal fonts or externally specified fonts. In the case of Knuth's typesetting language \TeX, fonts were intended to be created using METAFONT\cite{knuth}.

Figure \ref{zglyph} shows a $\mathscr{Z}$ (Z) in Ralph Smith's Formal Script font\footnote{\url{http://www.tug.dk/FontCatalogue/rfsf/}}. On the right, a screenshot taken in the Inkscape vector graphics editor shows the start/end points for each Cubic Bezier in the Spline defining the glyph outline\footnote{Inkscape activates the two adjacent control points after selecting one of the bezier start/end points; these are the two circles in Figure \ref{zglyph}}.

\begin{figure}[H]
\begin{minipage}[t]{0.5\textwidth}
\begin{figure}[H]
	\centering
	\includegraphics[width=1\textwidth]{figures/z.pdf}
\end{figure}
\end{minipage}
\begin{minipage}[t]{0.5\textwidth}
\begin{figure}[H]
	\centering
	\includegraphics[width=1\textwidth]{figures/z.png}
\end{figure}
\end{minipage}
	\caption{A glyph for the letter Z and a screenshot showing bezier start/end points as squares and diamonds}\label{zglyph}
\end{figure}
