Public speaking, also called oratory, is the act or skill of delivering speeches on a subject before a live audience.
The main objective of public speaking is to inform or change the audience's thoughts and actions. The function of public speaking is determined by the speaker's intent, but it is possible for the same speaker, with the same intent, to deliver substantially different speeches to different audiences.

Public speaking is frequently directed at a select and sometimes restricted audience, consisting of individuals who may hold different perspectives. This audience can encompass enthusiastic supporters of the speaker, reluctant attendees with opposing views, or strangers with varying levels of interest in the speaker's topic. Proficient speakers recognize that even a modest-sized audience is not a uniform entity but rather a diverse assembly of individuals.

Broadly, public speaking aims to either reassure an anxious audience or to alert a complacent audience of something important. Once the speaker has determined which of these approaches is required, they will use a combination of storytelling and informational approaches to achieve their goals.