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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