A characterset is a relationship between a set of glyphs (e.g. A 1 $) and numbers (e.g. 65 49 36). The examples given are from the 7-bit ASCII characterset.
A font (typeface) is a set of drawing instructions that tells the computer how to draw a given letter, e.g. W=4 diagonal lines (+more details). I'm not certain how fonts relate to charactersets; if you have Times New Roman on a Windows-1252 PC that draws 65 as A, then change the characterset to one where A isn't 65, does char 65 still draw A or does it draw something else? But anyway, fonts are the charactersets' graphical counterparts.