ChatGPT, or Generative Pre-training Transformer, is a type of artificial intelligence language model developed by OpenAI. 

OpenAI is an artificial intelligence research lab that consists of both for-profit and non-profit arms. It was initially founded by Elon Musk, Sam Altman, Greg Brockman, Ilya Sutskever, John Schulman, and Wojciech Zaremba in December 2015. However, it’s important to note that while Musk was one of the original co-founders, he has not been actively involved in the organization since 2018.

The GPT family of models was created through a two-step process involving pre-training and fine-tuning. In the pre-training phase, the model is trained to predict the next word in a sentence using a large amount of text data from the internet. It’s not explicitly told anything about the data or the nature of language itself, but learns patterns and structures by predicting what comes next.

During the fine-tuning phase, the model is further trained on a more specific dataset with human reviewers following guidelines provided by OpenAI. This allows the model to be more useful in generating human-like text that is contextually relevant and responsive to user inputs.

While GPT-3 was the latest model as of September 2021, subsequent iterations like GPT-4 also follow a similar process of creation but with advancements and refinements. This next generation GPT-4 version includes using more data, better fine-tuning processes, and improvements in the underlying machine learning algorithms or architecture to create a more powerful and accurate language model.