Resumo. This article introduces ChatGPT, a language model based on text generation developed by OpenAI. Built on top of the GPT-3.5 architecture, ChatGPT is capable of engaging in interactive conversations with users, answering questions, providing information, and even simulating natural conversations. The model is trained on large amounts of text data and uses an attention mechanism to learn language structure and generate coherent and relevant responses. The purpose of this article is to analyze and discuss the training process, main characteristics, challenges and applications of ChatGPT. ChatGPT represents an important step towards more sophisticated and interactive dialog systems, driving the advancement of artificial intelligence in the field of conversation.