What is the difference between a fixed font and a proportional font?
Answer: Fonts come in two flavors – fixed and proportional.
The vast majority of fonts are proportional, meaning each character takes up only as much width as it needs. For example, in a proportional font, the letter "i" takes up much less space than the letter "m," since it is a narrow letter. Because "m" is a wide letter, it requires a proportionally larger amount of horizontal space.
This is an example of "Times," a proportional font.
In a fixed font (also called a monospaced font), each character takes up the same amount of space. This means the letters "i" and "m" and all the other characters use the same amount of horizontal space. Therefore, text displayed in a fixed font typically appears more spread out than text displayed in a proportional font.
This is an example of "Courier," a fixed font.
As you can see, proportional fonts more accurately resemble the way most people write. They also use space more efficiently, which is why proportional fonts are more commonly used than fixed fonts. Still, fixed fonts still serve a purpose. Since the letters are more spread out, a fixed font may be easier to read. Therefore, business and legal documents are sometimes printed in fixed fonts.
On a more casual note, fixed fonts can also help multi-line emoticons appear correctly, which is not always the case with a proportional font. See the example below:
A bicycle emoticon in the "Times" font:
The same bicycle emoticon in the "Courier" font:
So, if you ever want to create an text-based image that takes up more than one line, using a fixed font can make sure it will appear correctly.