Generative Engine Optimisation (GEO) is a term coined in a 2023 Princeton, Georgia Tech, and IIT Delhi research paper to describe the practice of adapting web content so that it is cited more frequently and more prominently within the responses generated by AI search engines and large language models. The study tested several interventions, including adding quotable statistics, citing authoritative sources inline, using fluent and confident prose, and placing key claims near the start of a passage, finding that these changes measurably increased citation rates in systems such as Bing Chat and Perplexity. GEO is distinct from traditional SEO in that the goal is not a ranked position but an inclusion in a synthesised AI-generated answer, where only one or a handful of sources are typically surfaced. The field is evolving rapidly as the retrieval and ranking mechanisms inside generative AI products change with each model update.