Oracles

There are many types of computation that will be impractical to execute on the EVM. In spite of this, there are times when contracts will need the results of such computations. Eventually, many of these computations will be available via ABI or values can be pre-computed, logarithms are a good example of this. But there are other forms of computation such as random number generation that will require off-chain computation. The services that provide this off-chain computation are called Oracles.