Typography refers to the reproduction of letters on the page. You're probably familiar with a few different typefaces, such as Times Roman or Courier, but now you need to learn how to combine them.
You don't have to use type styles from ten different families to make a professional looking publication, but combining a few different typefaces improves contrast. There are only a few guidelines to keep in mind.
First, don't mix similar typefaces together. The whole purpose of combining them is to create contrast, so don't mix typefaces that are only slightly different. To make the right choices, you need to understand how typefaces are constructed, so we'll cover some terminology first.
There are two major categories: serif and sans serif.
Serifs resemble pen strokes and extend from the ends of letterforms: . Look at the lines extending at both ends of the letter a and the top of the letter g. These are called serifs, so this is a serif typeface.
Now look at these same letters again: . You'll notice that there are no serifs. The type face is Arial, a popular sans serif font (sans means without in French).
Serif typefaces come in three different styles: oldstyle, modern, and slab serif.