GPT-4 is a large language model created by OpenAI, which is an AI model that can understand and produce language that is creative and meaningful. Its biggest innovation is that it can accept text and image input simultaneously, and consider both while drafting a reply. It can comprehend human emotions, such as humorous pictures and describe images, which is beneficial for the visually impaired. GPT-4 can take into context up to 25,000 words, an improvement of more than 8x over its predecessor GPT-3.5. It performs well in language comprehension in English and 25 other languages. GPT-4 can do a lot of white-collar work, especially programming and writing jobs, while leaving manufacturing or scientific jobs relatively untouched. However, its output may not always be factually correct and is still prone to some of the flaws of its predecessor, such as hallucination.