In most general terms, a pun is a form of speech play in which a word or phrase unexpectedly and simultaneously combines two unrelated meanings.

Pun can be parted into two kinds from a macro-perspective: homophonic pun and homonymic pun; or we can part it into five kinds from a micro-perspective: homophionic pun, paranomsaia, antalaclasis, sylletic pun, aseismus. They have the same characteristics: 1) the utterance meaning may fall onto the different meanings of the same word or same (similar) pronunciation; 2) each pun had double contexts.

The studies on puns have been conducted from different angles, and Joel Scherazer has summarized the studies into four perspectives. The first is discourse analysis perspective. Puns could manipulate different levels and aspects of language, and it can also relate to other discourse units, processes, and contexts in various ways.

They can function both cohesively and disjunctively. They play a role in discourse cohesion in linking various utterances or parts of a discourse to each other. The seconds is from sociological perspective. In this perspective, pun is viewed both in terms of social structure and social interaction. In addition to being used by speakers or recipient-responders to display understanding of presented narrative material, puns can be used by speakers to obtain the floor in a conversation, to change the topic or to relieve tension by its humorous effect. The third is from ethnographic perspective.

This perspective raises questions of cross-cultural comparison. In different cultures, there are differences in the role of puns in discourse patterns and structures, as well as the topics for which puns are considered appropriate and the attitudes toward puns. The fourth is from psychoanalytic perspective, which is developed by Freud in his study of wit in general. He stresses ambiguity and condensation in puns—the merger of several meanings, including unconscious meanings, into a single item.