Web Search
There are a lot of questions that Siri can answer directly using common knowledge sources like Wikipedia, but right now if you ask your HomePod for something that requires a deeper web search, Siri will simply respond with an apology saying it “can’t search the web from here.”
In the coming update, however, it looks like Siri will now take the much more logical step of sending the web search results to your iPhone, likely letting you know to pull out your iPhone and take a look, and using voice recognition to send it to the iPhone of the user who made the actual request, similar to how secure personal requests work right now.