====== Basic Docker Concepts =====

Understand the fundamental concepts of Docker.

> //Docker uses images, containers, volumes, and networks to isolate and manage applications.//

===== Overview =====

Docker uses several key concepts to isolate and manage applications. Understanding these concepts is essential for effective Docker usage.

===== Images =====

Images are read-only templates that contain everything needed to run an application. They are stored in registries like Docker Hub.

**Key points:**
  * Read-only templates
  * Contain application code and dependencies
  * Stored in registries (Docker Hub, private registries)
  * Built from Dockerfiles
  * Can be versioned with tags

===== Containers =====

Containers are running instances of images. They are isolated from each other and the host system.

**Key points:**
  * Running instances of images
  * Isolated from each other and host
  * Can be started, stopped, and removed
  * Lightweight compared to virtual machines
  * Share host kernel

===== Volumes =====

Volumes provide persistent storage for containers. Data in volumes survives container restarts and removals.

**Key points:**
  * Persistent storage for containers
  * Data survives container restarts and removals
  * Can be named volumes or bind mounts
  * Managed by Docker
  * Can be shared between containers

===== Networks =====

Docker networks allow containers to communicate with each other. By default, containers on the same network can reach each other by service name.

**Key points:**
  * Enable container communication
  * Service discovery by name
  * Isolated from external networks
  * Can be bridge, overlay, or host networks
  * Custom networks for better control

===== Common Docker Commands =====

```bash
docker ps                    # List running containers
docker images                # List images
docker run image-name       # Run a container
docker stop container-id     # Stop a container
docker rm container-id      # Remove a container
docker exec -it container-id bash  # Execute command in container
docker logs container-id     # View container logs
```

===== See Also =====

  * [[hosting:docker:start|Docker Overview]]
  * [[hosting:docker:installation|Docker Installation]]

Last updated: 2026-06-19
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