What is Docker
Application containerization platform
Docker — a platform for building, deploying, and running applications in isolated containers.
Core Components
- Docker Engine — container runtime environment
- Dockerfile — instructions for building images
- Docker Image — template for creating containers
- Docker Container — running instance of an image
- Docker Hub — registry of ready-made images
Benefits
- Isolation — applications don't conflict with each other
- Portability — works the same everywhere
- Speed — starts in seconds (vs minutes for VMs)
- Efficiency — fewer resources than virtualization
- Versioning — image version control
Business Applications
Docker standardizes development environments, simplifies CI/CD, and enables microservices scaling.