The purpose of a prompt in artificial intelligence is to provide an initial input or directive that guides the AI's response. For natural language processing models, prompts can be in the form of questions or statements that define the context for generating text. A well-crafted prompt ensures that the AI understands the desired outcome and can produce coherent, relevant information. In tasks like content generation, chat interactions, or coding assistance, the quality of the prompt significantly affects the accuracy and usefulness of the responses generated by the AI system.