monospaced font, fixed-width font, non-proportional font
a fixed-pitch font (as opposed to a proportionally spaced font [like Times New Roman, Arial, Helvetica, Verdana]) is one in which every letter occupies the same amount of horizontal space on the line, regardless of whether it is a lower case i or a capital M. Fonts used for typing scripts are 10 pitch, meaning there are 10 characters per horizontal inch, and 12 points, which allows six lines of type per vertical inch. The most often used fonts in screenwriting are Courier and Courier New. (Riley, 2005, p. 2)