Acronyms and initialisms are abbreviations formed from the initial components in a phrase or a word. These components may be individual letters (as in CEO) or parts of words (as in Benelux and Ameslan). There is no universal agreement on the precise definition of the various terms (see nomenclature) nor on written usage (see orthographic styling). In English and most other languages, such abbreviations have historically had limited use, but their coinage and use became much more common in the 20th century. As a type of word formation process, acronyms and initialisms are viewed as a subtype of blending.

The term acronym is the name for a word from the first letters of each word in a series of words (such as sonar, created from sound navigation and ranging). Attestations for "Akronym" in German are known from 1921, and for "acronym" in English from 1940. While the word abbreviation refers to any shortened form of a word or a phrase, some have used initialism or alphabetism to refer to an abbreviation formed simply from, and used simply as, a string of initials.^{[citation needed]}

Penn & Teller (Penn Jillette and Teller) are American illusionists and entertainers who have performed together since the late 1970s, and are known for their numerous stage and television shows. Their current Las Vegas show is an amalgam of illusion and comedy. Penn Jillette is a raconteur; Teller generally does not speak while performing, although his voice can occasionally be heard during their performance. They specialize in gory tricks, exposing frauds, and performing clever pranks. More recently they have become associated with atheism, scientific skepticism, and libertarianism, particularly through their television show Penn & Teller: Bullshit!.

Penn Jillette and Teller were introduced to one another by Weir Chrisimer, and they performed their first show together at the Minnesota Renaissance Festival on 19 August 1975. From the late 1970s through 1981, Penn, Teller, and Chrisimer performed as a trio called "The Asparagus Valley Cultural Society" which played in San Francisco at the Phoenix Theater. This act was sillier and less "edgy" than today's Penn & Teller act.^{[citation needed]} Chrisimer helped to develop some bits that continued, most notably Teller's "Shadows" trick, which involves a single red rose.