How JavaScript Packages Actually Work
If you’ve worked with JavaScript even once, you’ve seen package.json, package-lock.json, and the infamous node_modules folder. But what do these actually do, how do they work together, and why do they confuse so many developers?
In this video, I break down the entire JavaScript package system using npm.
You’ll finally understand:
✅ What package.json REALLY controls
✅ Why package-lock.json exists & why it matters
✅ What’s actually inside node_modules
✅ How npm installs dependencies behind the scenes
✅ The difference between npm install vs npm ci
✅ How to generate these files/folders correctly
✅ Best practices that every beginner should know
By the end, the whole JavaScript / npm ecosystem will finally make sense. No more confusion. No more random errors. Just a clean, foundational understanding of how every JS project works under the hood.
Whether you’re working with React, Node, Express, Next.js, or any JavaScript framework, this breakdown will save you hours of frustration and help you build projects the right way.
Timestamps:
0:00 - Intro
0:50 - Packages/npm
3:49 - package.json
4:52 - The Three Layers
5:21 - package.json
10:18 - package-lock
17:13 - node_modules
22:03 - Git considerations
23:45 - how to generate
24:03 - npm install (npm i)
29:33 - npm clean install (npm ci)
32:01 - npm i VS npm ci
34:38 - Simple best practices