Large language models (LLM) are the product of neural networks, a relatively recent innovation in the field of computer intelligence.
Since these systems are surprisingly adept at producing natural sounding language, and is good at create answers that sound correct (and sometimes actually happen to be) marketers have seized on this as an innovation, called it AI (a term with a complicated history), and have started slapping it onto every product.
And there's a huge difference between fifty degrees below zero and absolute zero. But both are lethal to humans if exposed to it for a night.