GPT stands for Generative Pre-trained Transformer, a deep learning neural network model based on the Transformer architecture, proposed by OpenAI in 2018. The GPT model is pre-trained on large-scale text data and has powerful language understanding and generation capabilities. It can be used for a variety of natural language processing tasks such as text generation, dialogue systems, machine translation, sentiment analysis, and question-answering systems.

The core technology of the GPT model is the Transformer architecture, which effectively captures contextual information, handles long-distance dependencies, and implements parallel computing through the self-attention mechanism. The pre-training process of the GPT model usually uses the objective function of the language model, that is, predicting the probability of the next word based on the previous k words, and then fine-tuning on a specific task. The figure below shows the various stages of GPT development.