Data and oracles

Chains cannot see the outside world on their own: someone has to bring them prices, events, and verifiable data. Oracles are that bridge, which is why they are critical DeFi infrastructure: a lending protocol is worth exactly what the prices it liquidates with are worth. The category is contested between on-chain aggregation models and first-party data sources, and the technical detail matters more than it seems, because the update design decides how the oracle behaves exactly when markets move violently.

What to compare: Compare who supplies the data and with what incentives, how prices update during extreme volatility, and how many major protocols depend on each network, because that is where systemic risk lives.