What is an answer engine?
An answer engine gives you a written answer instead of a list of links. It will often name the sources it used. ChatGPT, Perplexity, Claude and Google's AI surfaces all work this way.
The basic process is retrieval, then generation. The engine finds relevant passages and writes an answer from them. What gets retrieved decides which sources appear.
The line between answer engines and search engines is blurring. The useful distinction is simple: the answer is the product, not the link.
Why it matters for product builders
If you're missing from an answer engine, there's no page ranking to inspect. The only way to know is to ask the question and check the answer.