The serif, or cross-line at the end of a stroke, probably dates from early Rome. Father Edward Catich proposed in his seminal work.
The Origin of the Serif, that the serif is an artifact of brushing letters onto stone before cutting them. Serif types are useful in text because the serifs help distinguish individual letters and provide continuity for the reader’s eye.
Serifs come in many styles. Compare the tapered serifs of Kepler® to the slab serifs of Chaparral® and the wedge serifs of WarnockTM.
Typefaces without serifs are called sans serif (sans is French for without) designs. The first sans serif type design is credited to William Caslon in England in 1816. Sans serif designs are also sometimes referred to as gothic or grotesque designs.