eli5 — explain it to someone who knows nothing

The topic is whatever the user named. With no topic named, it is the one the conversation is already on. The audience is someone with zero background: no vocabulary, no context, no patience for a definition that needs another definition.

The contract

1. A page, not a paragraph. The output is one self-contained HTML page, big visuals first, words second. Open it when it is written.
2. Picture carries the idea, words label it. If the page still makes sense with the text removed, it is working. Aim for a caption per picture, not a paragraph per picture.
3. Everyday objects only. Compare to things a person has physically handled: boxes, keys, queues at a counter, post, a light switch. Never explain one unknown with another unknown.
4. Zero jargon, and zero smuggled jargon. No term appears without being shown first. "It caches" is jargon; "it keeps a copy nearby so it doesn't have to walk back" is the same fact.
5. Simple, never false. When the simplification would make something untrue, say what got left out, in one line, at the end. A comfortable lie is worse than a hard truth.
6. No condescension. Simple words, adult tone. The reader is new to the topic, not a child.