Check out example codes for "express serve html". It will help you in understanding the concepts better.

Code Example 1

const path = require('path')
const express = require('express')

const app = express()

const port = process.env.PORT || 3000
const publicDirectoryPath = path.join(__dirname, '../public')

app.use(express.static(publicDirectoryPath))

app.listen(port, () => {
    console.log(`Server is up on port ${port}!`)
})

Code Example 2

express.static(root, [options])

Code Example 3

app.use(express.static('public'))

Code Example 4

app.use(express.static('public'))
app.use(express.static('files'))

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