Punctuation refers to the symbols or marks used in writing to separate sentences and clarify meaning. The main symbols are the period, comma, semicolon, colon, and question mark. Punctuation helps prevent miscommunication by indicating pauses and emphasis. The comma specifically is used to separate elements in a list, set off introductory words, join two independent clauses, and set off quoted material from attribution. Proper use of punctuation symbols like the comma helps writing be clear and unambiguous.