GPT-4 (Generative Pre-trained Transformer 4) is an AI-based language processing architecture developed by OpenAI. It is the fourth generation of the GPT series, which is based on machine learning and natural language processing (NLP). GPT-4 is designed to generate human-like texts and can be applied to various tasks such as text completion, translation, text summarisation, question-answer scenarios and many others.

The GPT models are trained to recognise patterns in text data and use these patterns to respond to given input in a coherent and relevant way. GPT-4 uses a larger number of neurons and training data compared to its predecessors, resulting in better performance and accuracy when processing speech. However, it should be noted that despite its impressive capabilities, GPT-4 is still an AI and is unable to match human intuition or emotional intelligence.