Is there any difference between an excerpt and a quote?

Below are the definitions from online dictionaries. It looks like an excerpt is a formal quote, am I right?

excerpt ( ) n. A passage or segment taken from a longer work, such as a literary or musical composition, a document, or a film.

quote v. , quoted , quoting , quotes . v.tr. To repeat or copy the words of (another), usually with acknowledgment of the source.

Informal. A quotation

Thanks in advance.
Excerpts are generally longer quotes, and as your definition says, come from written or scripted pieces; quotes needn't.