What is Docker?
Docker is a tool that packages code, libraries, and all dependencies into a single unit called a Container.
Problem it solves:
It eliminates the "It works on my machine" issue. It ensures that an application runs exactly the same way in development, testing, and production environments without dependency conflicts.
How it works:
• Dockerfile: A script containing commands to assemble an image.
• Image: A read-only blueprint of the application environment.
• Container: A live, isolated process where the image runs.
Unlike Virtual Machines, Docker shares the host OS kernel instead of bundling a full OS, making it lightweight and fast.
Scenario:
If your app needs Node.js v18 and specific libraries, you define them in a Dockerfile. When you move this to a server, Docker sets up that exact environment automatically, so you don't have to install anything manually.
August 23, 2026 112 1
