For generating responses, chatbots rely on techniques like retrieval based methods and generative models. Retrieval based chatbots identify and return the most similar response from a database, while generative models can produce new natural responses based on training. The response is then sent back to the user through voice or text. https://logcla.com/blogs/399853/Conversational-AI-How-Chatbots-Are-Evolving-Natural-Language-Interactions