Satire is the ridicule of vice or folly. Its (ostensible) goal is to take an individual person, a type or person, an individual folly, or a type of folly, and expose it to public view. Note that satire doesn't have to be funny, though it very often is.

The two most influential classical Latin satirists were Horace and Juvenal; Horace was the more gentle, general, and good-natured, while Juvenal had a sharper edge to his satires. Satires that follow these traditions are classified as Horatian or Juveanlian.

A third kind of satire is harder to define: it's known as Menippean or Varronian satire. Although Horatian and Juvenalian satires are often formal verse satires, a well recognized genre, satire need not be in verse, and Menippean satire often isn't. But it's also characterized by an almost formless form -- Menippean satires are conventionally chaotic in organization, and it's usually difficult (if not impossible) to pin down the specific targets of ridicule. Some good examples are Rabelais's Gargantua and Pantagruel and Laurence Sterne's Tristram Shandy. The Russian theorist Mikhail Bakhtin devotes a lot of his attention to Menippean satire in general and Rabelais in particular, drawing attention to what he calls their dialogism.

Satire is not the same thing as parody, although satire can use parody as a technique.

From the Guide to Literary Terms by Jack Lynch.