What is a blockchain oracle? Oracles connect blockchains to external systems so smart contracts can act on verified data—prices, interest rates, reserves, weather, identity, and more. Without that bridge, contracts stay blind to the world.
Key ideas
Determinism: nodes must all get the same result; arbitrary HTTP calls would break consensus. Oracles preserve determinism by moving verification on‑chain (signatures/timestamps) while collecting data off‑chain.
Data domains: price feeds, proof‑of‑reserve, rate indices, randomness, cross‑chain reads.