GPT, GPT-2, and GPT-3 are large language models based on the transformer architecture, with GPT-3 being the most recent release from OpenAI as of 2020 [6]. GPT models are known for their generative capabilities and are used in natural language processing tasks [7]. The rise of GPT models represents a significant AI research breakthrough, enabling automation and improvement of various tasks such as language translation, document summarization, and content generation [4].

The latest offering from OpenAI is ChatGPT, which is a free-to-use model that assists users in getting answers, finding inspiration, and enhancing productivity [5]. It's important to note that there are also AI detection tools, like GPTZero, which help determine if a document was generated by a large language model like ChatGPT [8].

In summary, GPT models are advanced large language models that leverage the transformer architecture for natural language processing tasks, with the latest being ChatGPT, and there are detection tools available to identify AI-generated content.