The pun, also called paronomasia, is a form of word play which suggests two or more meanings, by exploiting multiple meanings of words, or of similar-sounding words, for an intended humorous or rhetorical effect.These ambiguities can arise from the intentional use and abuse of homophonic, homographic, metonymic, or metaphorical language. A pun differs from a malapropism in that a malapropism uses an incorrect expression that alludes to another (usually correct) expression, but a pun uses a correct expression that alludes to another (sometimes correct but more often absurdly humorous) expression. Henri Bergson defined a pun as a sentence or utterance in which "two different sets of ideas are expressed, and we are confronted with only one series of words".Puns may be regarded as in-jokes or idiomatic constructions, given that their usage and meaning are entirely local to a particular language and its culture. For example, camping is intense (in tents).
Puns are used to create humor and sometimes require a large vocabulary to understand.
I think that puns are also used for satirizing disadvantages of human character.