DeFi oracles are third-party services enabled by blockchain smart contract technology to access real-time asset prices. Generally, the blockchain does not store realistic asset prices in its storage system. The DeFi oracles access such information from a real-time environment and perform the crypto asset exchanges among the entities. The DeFi oracles are in two forms that are inbound and outbound. It extracts realistic data from two resources that are described as follows.
• Hardware Oracles
• Software Oracles
The sensors and bar code scanners are hardware oracles transmitting real data to the DeFi smart contract in digital form. Unlike hardware oracles, software oracles like the market price information of crypto assets are virtual and transmitted to the smart contract. Some of the DeFi oracle coins are described as follows.
• Band Protocol