Docker is a platform for developing, shipping, and running applications in lightweight, portable containers.
Docker containers package code with all dependencies, ensuring "works on my machine" works everywhere. Standard for application packaging in 2026. Docker Desktop is paid for >250-employee companies. Alternatives: Podman, containerd. Container security tools: Snyk, Wiz, Aqua. Kubernetes uses containers (typically Docker-built) as its unit of work.
Docker made consistent, reproducible application environments the default. It is the unit that most modern CI/CD pipelines, Kubernetes deployments and cloud platforms operate on.
A developer writes a Dockerfile that packages the app with its exact Node version, system libraries and config. The container runs identically on the developer's laptop, CI, staging and production — eliminating "works on my machine" bugs.
Docker containers are not virtual machines. They share the host kernel and are much lighter, but they also offer weaker isolation than a full VM.
Keep images small by using slim base images and multi-stage builds; smaller images deploy faster, scale faster and have a smaller attack surface.
Docker falls under the Hosting category.
These tools put docker into practice. Compare features, pricing, and ratings:
Now that you understand Docker, explore the best tools in this category.