What is performativity in philosophy?

Performativity as a concept was first developed by the philosopher of language John L. Austin to define the capability of language as a mode of action and not just as a mode of description. It ran counter to the positivist view of speech as essentially comprising utterances that were either true or false. Marriage vows, promises of help, judicial verdicts, placing of bets are all instances of performative utterances that signify indulgence, and not any verifiable description.

Source: The Hindu, 4/02/2019