Introduction to net module

Consider the following server.js code snippet:

const net = require('node:net');
const port = 3000;

const server = net.createServer((client) => {
  console.log('Client connected');
});

server.listen(port, () => {
  console.log(`Server is listening on port ${port}`);
});

If this server is already running, and we attempt to start another instance, we might encounter a specific error. Which error is most likely to occur?