https://nodejs.org/en/docs/guides/blocking-vs-non-blocking/
const fs = require('fs'); const data = fs.readFileSync('/file.md'); // blocks here until file is read console.log(data); // moreWork(); will run after console.log
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const fs = require('fs'); fs.readFile('/file.md', (err, data) => { if (err) throw err; console.log(data); }); // moreWork(); will run before console.log