GPT-4 is the newest version of OpenAI's language model that can understand and generate natural language. It shows improvements over GPT-3.5 in its ability to take visual inputs, be steered more precisely by the user, refuse unsafe requests, and score higher on factual benchmarks. Potential applications of GPT-4 include customer service, translation, content creation, and research. However, its adoption may displace some jobs and raises ethical issues that need addressing through education, job retraining, and responsible development of the technology.