Oracle service and oracle smart contract

I read this article https://medium.com/@robinagist/building-an-ethereum-oracle-with-web3-js-1-0-1272b59cfc31 but there are some things I didn’t understand. Does the oracle need a node (like geth or parity) to communicate with the oracle smart contract?
At this link there is the code https://github.com/robinagist/EthereumWeatherOracle in wxoracle.js I did not understand the sleep function what it is for.