Short answers, pulled from the story.
A parody is a creative work designed to imitate, comment on, or mock its subject through satirical or ironic imitation. The word derives from the Greek parodia, built from para, meaning beside, counter, or against, and oide, meaning song, which is why it is sometimes taken to mean counter-song.
According to Aristotle in the Poetics, Hegemon of Thasos was the inventor of a kind of parody. By slightly altering the wording in well-known poems, Hegemon transformed the sublime into the ridiculous.
A satire makes fun of the real world and points to a specific vice to mock it, while a parody is a derivative of a specific work or genre and leans toward playful humor without always attacking its target. Pastiche imitates a work but is neither transformative nor humorous, which led critic Fredric Jameson to call it a blank parody, or parody that has lost its sense of humor.
Parody is protected under the fair use doctrine of United States copyright law, especially when the use is transformative, such as a critique or commentary. In Campbell v. Acuff-Rose Music, Inc., the Supreme Court ruled that 2 Live Crew's rap parody of Oh, Pretty Woman was fair use.
The reputation of a parody sometimes outlasts the reputation of what it parodies. Don Quixote, which mocks knight errant tales, is far better known than Amadis de Gaula, and many of Lewis Carroll's parodies of Victorian verse are better known than the largely forgotten originals.
Mel Brooks became one of the most famous film parodists after The Producers won an Academy Award and a Writers Guild of America Award in 1967, going on to make Blazing Saddles, Young Frankenstein, and Spaceballs. Monty Python made Monty Python and the Holy Grail and Life of Brian, and the team of David Zucker, Jim Abrahams, and Jerry Zucker created the Airplane!, Hot Shots!, and Naked Gun series.
In the UAE and North Korea, parodies are not allowed and can be considered insulting, and the person who makes a parody can be fined or even jailed. By contrast, countries including the United States, Canada, and the United Kingdom provide copyright exceptions that cover parody.