show me openai gpt models

OpenAI has developed several versions of its GPT (Generative Pre-trained Transformer) models. Here's a brief overview of the main models released:

**GPT-1**: The first version of the Generative Pre-trained Transformer, introduced in 2018. It laid the groundwork for using transformer architectures for language generation tasks.

**GPT-2**: Released in February 2019, GPT-2 was a significant improvement over its predecessor. It was initially withheld due to concerns about misuse but was later fully released. It features 1.5 billion parameters and was notable for its ability to generate coherent and contextually relevant text.

**GPT-3**: Launched in June 2020, GPT-3 has 175 billion parameters and provided significant advances in natural language understanding and generation. It has been widely recognized for its ability to perform a wide range of language tasks with little to no fine-tuning.

**GPT-3.5**: This series, including models like "davinci-003," builds upon the capabilities of GPT-3, focusing on improved performance and reliability in generating text and handling specific tasks.

**GPT-4**: Released in March 2023, GPT-4 introduced new capabilities and improvements in reasoning, creativity, and understanding of nuanced prompts. It's available in different configurations and is designed to handle more complex queries.

**ChatGPT**: A conversational model based on GPT-3.5 and GPT-4, fine-tuned for dialogue, allowing for more interactive and conversational interactions.

**Codex**: A specialized version of GPT-3, trained specifically for programming tasks. It powers tools like GitHub Copilot, assisting with code generation and understanding.

These models are accessible through OpenAI's API and various applications, allowing developers and businesses to integrate advanced AI capabilities into their products.