Punctuation includes pretty much everything that is not the combination of letters
from the alphabet into what are commonly known as words. Just look at any standard keyboard. If it doesn’t
have an alphabet letter on it, it's a pretty good bet it has something to do with punctuation. There's a bunch of those
buggers, and they all mean something different, and if you use the wrong one, put one in where it doesn't belong, or you leave
one out, it can change things a lot more seriously than you might suspect. Just ask those folks in Purgatory.
An Introduction to Punctuation