We spend most of our time here talking about proving. Tonight let's look at the other side of it, the verifier. 🔍 A verifier is the thing that does the checking. It's a piece of code that you give it a result along with the proof that came with it, and it tells you whether the proof holds up. Checking is quick. The verifier runs a short fixed sequence of math and returns true or false. It never redoes the original work and it never needs the private data behind the claim. Confirming something is far cheaper than doing it. 📱 Because that check is so cheap, a verifier can run almost anywhere. A server, an app on your phone, a browser tab. On a blockchain it's a smart contract, which is where most people first meet the idea, though plenty of zero-knowledge proofs get verified nowhere near a blockchain. ✅ In practice this is far less complex than it sounds. If you wanted to check a proof yourself, you'd open a page, upload the proof, and wait a moment for a true or false to come back. That's the entire experience. Which is a big part of why zero-knowledge proofs are so powerful. Anyone, anywhere, at any time can confirm something is true, and they need nothing from whoever produced it.