"AI" has unfortunately become synonymous with "LLM," even though LLM's are only a subset of AI.
"Autocomplete" seems to be the simplest way of explaining it is just fancy pattern recognition.
Slightly longer:
> Traditionally programming meant explicitly telling computers how to do something. 'AI' just gets the inputs and outputs, and figures out the 'how' own its own.
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I share these explainer videos when people ask me to explain AI to them: