According to the Treasury of Alphabets and Lettering, there are two main categories of modern lettering: Roman and Blackletter.
Blackletter fonts tend to be heavy and dark, and may reflect medieval styles of lettering.
Roman is a standard vertical style of lettering and includes several categories, or as designers call them, families.
Oldstyle lettering has even strokes and small serifs---which, according to Gooding, are lines or "embellishments projecting from the main stroke of a letter."
Oldstyle fonts are frequently used in books and magazines because of easy legibility.
Popular examples include: Garamond, Bookman Old Style and Goudy Old Style.
Transitional typefaces have greater contrast in stroke thickness and wider serifs. Transitional fonts include: Baskerville Old Face, Dante and Leyden.
In "Family Classifications of Type," an online tutorial on the Spokane Falls Community College website, contemporary lettering is described as having "extreme contrast between thick and thin strokes" and very light serifs. Bodoni is a classic modern typeface.
This typeface is easy to distinguish because there is no serif at the end of the letter stroke. The "Family Classifications" tutorial also points out that sans serif lettering has "little variation between thick and thin strokes." Examples of sans serif fonts include: Futura, Century Gothic and Tahoma.
According to "Family Classifications," slab serifs (or Egyptian) fonts have fairly even thickness and "heavy serifs with squared-off ends." Slab serifs were especially popular in advertisements throughout the 1800s because of their attention-grabbing appearance. Clarendon, Playbill and Alcade are examples of Slab Serif fonts.