Abstract: Large Language Models receive a lot of attention in the media these days. We have all experienced that generative language models of the GPT family are very fluent and can convincingly answer complex questions. But they also have their limitations and pitfalls. In this presentation I will introduce Transformer-based language models, explain the relation between BERT, GPT, and the 130 thousand other models available on https://huggingface.co. I will discuss their use and applications and why they are so powerful. Then I will point out challenges and pitfalls of Large Language Models and the consequences for our daily work and education.