Query fan-out is breaking a complex question into several related searches. The system gathers sources for the individual parts and uses them to build the answer.
What is query fan-out?
A query like "what SEO does a new online store need" can lead to sub-searches about indexing, categories, filters, keywords and speed. The exact breakdown depends on the system.
Google describes this principle for its AI features. You can't assume every model uses the same number of queries, the same sources or the same logic.
What it changes for content
One optimized phrase may not cover the full context of a question. The content should explain the main decisions, relationships and conditions the user needs.
That doesn't mean a separate URL for every sub-question. Intent, the scope of the topic, SERP overlap and clarity for the visitor decide how you split it.
How to do it in practice
Start with the user's main need and map the related questions. Some belong as sections on one page. Others may need their own article or tool.
Connect the pages with relevant internal links. Every URL needs a clear role and value of its own. Another variant of the keyword isn't enough.