is express the main framework code example

Example 1: node.js express

const express = require('express')
const app = express()
const port = 3000

app.get('/', (req, res) => res.send('Hello World!'))

app.listen(port, () => console.log(`Example app listening at http://localhost:${port}`))

Example 2: what is express.js

Express is a minimal and flexible Node.js web application framework
that provides a robust set of features for web and mobile
applications.