Punctuation refers to the marks used in writing to separate sentences, clarify meaning, and indicate pauses or emphasis.
Comma: A comma is a punctuation mark used to separate items in a list, join independent clauses, and indicate pauses in a sentence.
Period: A period is a punctuation mark used at the end of a declarative sentence or an abbreviation.
Exclamation Point: An exclamation point is a punctuation mark used to show strong emotion or emphasis in a sentence.