ChatGPT

ChatGPT is the product OpenAI launched in November 2022 that genuinely brought AI assistants into the mainstream. It started on GPT-3.5 and broadened with the release of GPT-4 and later GPT-5. The success of the chat interface popularized Prompt Engineering and pushed the whole industry to organize around conversational use cases. Today ChatGPT is the default reference point for what people mean by an AI assistant.