What are Environment Variables, and how do I use them? (get,set)

5:46   Configure Node.js Environment Variables for Local Development & Production 4:03   Node.js Environment Setup: Development vs Production (dotenv Tutorial) 5:37   Learn How Companies Deploy Code to Production Environment [In 5 Mins!] 8:41   Difference Between Development, Staging, and Prod Environment? 0:42   How to use a .env file to load environment variables in a dev container 5:26   How to Use Environment Files (.env) in Node.js - Tutorial (dotenv) 3:26   Deploying dotenv (.env) files to production (lol, don't) 3:14   localhost:3000 vs Production – How .env Saves Your Vibe App 3:36   Types of Software Development Environments | Local Development Environment | Production Environment 1:51   How to handle Local Environment variables in React(Vite) Project. 1:39   How to Properly Include .env.production in Your NextJS Docker Container 1:50   Managing Two .env Files in Your React Project: Development vs. Production 1:32   Solving the process.env.NEXT_PUBLIC Variable Issue in Next.js Production Deployments