🐳 Docker Sandbox & Lab
docker run -d nginx in the terminal.Download the 'redis' image into local cache using 'docker pull redis'.
Run an Nginx container in background on port 80: 'docker run -d -p 80:80 nginx'.
Start a named container with '--name my-cache redis'.
The Three Ideas You Need First
A quick primer before you jump into advanced commands. Skim these concepts, then experiment in the terminal above.
What is Docker?
Docker packages an application with everything it needs, code, runtime, libraries and settings, into a single portable unit called a container. It runs the same on your laptop, a teammate's machine, or production, killing the classic "it works on my machine" problem.
What are containers?
A container is a lightweight, isolated process created from a read-only template called an image. Unlike heavy virtual machines, containers share the host OS kernel, so they start in seconds and use far fewer resources. You can run dozens at once.
What is this playground?
A safe, simulated Docker environment that runs entirely in your browser. You type real Docker commands and see realistic output, but nothing runs on your computer and nothing can break. Guided steps check your work and track your progress automatically.
How the In-Browser Simulation Engine Works
Unlike platforms that provision heavy remote virtual machines with cold start delays and time limits, this playground runs a high-fidelity client-side state machine implemented in TypeScript. Commands execute instantly in your browser memory with full state persistence, realistic latency simulation, and mock image registries. It is 100% safe to run destructive commands like pruning or deleting volumes without affecting your local system.