Quotation is the repetition of one expression as part of another one, particularly when the quoted expression is well-known, indicated by quotation marks.

"what's a quotation mark"?
"commas and periods always go inside the quotation marks in american english. dashes, colons, and semicolons always go outside the quotation mark

Do periods goes inside a quotation mark?

When would you use a quotation mark?

*laughing out loud*