What is Docker?
Docker is a platform used to package your applications, such as a web app running PHP, code, libraries, databases, Nginx configuration, Node.js, React.js, etc. It creates an isolated environment from your main Windows/Linux system, called a container.
These containers share the kernel of the host OS, making them lighter, faster to start, and more resource-efficient than virtual machines. Docker is not a virtual machine like traditional virtualization tools (e.g., VirtualBox, VMware).
Example:
You’re working on an application built with Node.js, using Redis for caching and MongoDB for data storage. Normally, you’d have to install and configure each component individually.
But with Docker, you just need to write a docker-compose.yml file that defines three containers: one for the Node.js app, one for Redis, and one for MongoDB.
Once your configuration is ready, you can launch the entire system with a single command:
docker compose up -dThe whole stack will spin up automatically, just like your development environment.
No manual installation, no version mismatch, no dependency on the host OS—Windows or Linux.
How does Docker work?
Unlike virtual machines, Docker doesn’t install a full OS inside each container. Instead, it shares the host’s kernel, making containers lighter, faster, and less resource-hungry.
A virtual machine might take some time to boot up. A Docker container can start in a few seconds—or even under a second.
What is Docker used for?
- Application development: No need to install complex environments. If it works on your machine, it works anywhere.
- Deployment: Push containers to servers and run. No need to reinstall MySQL, PHP, Redis…
- Testing & CI/CD: Run tests in containers, ensure clean code across all environments.
- Microservices: Each service runs in its own container. Easy to scale, easy to maintain.
- Learning environments: Try PostgreSQL, Kafka, Nginx… in seconds without messing up your system.
Advantages of Docker
- Lighter and faster than virtual machines.
- Strong environment isolation: each container runs independently.
- Easy to share and replicate: one config file, anyone can run it.
- Automation-friendly: build, test, and deploy using standard CI/CD pipelines.
- Consistent behavior across all OSs (as long as Docker is installed).
Disadvantages of Docker
- Requires learning new concepts: Dockerfile, volume, network, compose…
- Docker on Windows is slower than on Linux due to WSL2 overhead.
- Not suitable for traditional GUI-based applications.
- Harder to manage when the project grows → may need Docker Compose or Kubernetes.
Docker on Windows vs Linux
| Criteria | Docker on Windows | Docker on Linux |
|---|---|---|
| Kernel | Runs via WSL2 or Hyper-V | Uses Linux kernel directly |
| Performance | Good but slightly slower | Optimal, native, stable |
| Installation | More complex, requires Docker Desktop | Simple with apt/yum |
| File system (volume) | May face permission errors, slower I/O | Smooth, reliable |
| Production usage | Not recommended | Widely used in real-world servers |
Using Docker for development on Windows is totally fine.
But when it comes to running in production—Linux is the preferred choice.
Docker doesn’t just help your app “run”—it ensures it runs the same everywhere, from dev machines to real servers. It simplifies your workflow, saves setup time, and helps you avoid many frustrating bugs.
And if you’re ready to explore, here are the next steps: