What is npm? A Beginner's Guide to Node Packages

npm (Node Package Manager) is the world's largest software registry. It gives you access to millions of code packages that solve common problems.

What is npm?

npm is a tool that comes with Node.js. It lets you install, share, and manage code packages. Instead of writing everything from scratch, you can use packages that others have created.

Basic npm Commands

# Initialize a new project
npm init -y

# Install a package
npm install express

# Install a package globally
npm install -g nodemon

# Install a development dependency
npm install --save-dev jest

# Remove a package
npm uninstall express

# See outdated packages
npm outdated

package.json

Every Node.js project has a package.json file. It lists your project's dependencies and scripts:

{
  "name": "my-app",
  "version": "1.0.0",
  "dependencies": {
    "express": "^4.18.0"
  },
  "devDependencies": {
    "jest": "^29.0.0"
  },
  "scripts": {
    "start": "node app.js",
    "test": "jest"
  }
}

Popular npm Packages

Package	Purpose
express	Web framework
lodash	Utility functions
axios	HTTP requests
dotenv	Environment variables
nodemon	Auto-restart server

npm Scripts

Custom scripts automate tasks:

{
  "scripts": {
    "start": "node app.js",
    "dev": "nodemon app.js",
    "test": "jest",
    "build": "webpack --mode production"
  }
}

Run with npm run dev, npm test, etc.