A: Hi Sebastien!

Data search: there's no live web or data search, the AI writes from its own knowledge plus your prompt. For niche or specialised topics, importing or pasting in your own source material gives the most accurate results, so yes, bringing your own knowledge is the way to go for anything specialised.

Fiction: it uses a story bible that keeps your characters, world and plot consistent across chapters, and across multiple books via the Series tool. You set the premise and characters in your prompt, and it builds and follows that bible as it writes, so the world and persona coherence is handled for you.