What is a Container?
#42 · Level 3 · Modern architecture · ContainersConcept
Section titled “Concept”A container is a box that packs an app together with everything it needs to run. It holds the app’s code, libraries and settings, so it runs the same way anywhere. A container starts from an image — an image is the prepared design or template for a container. It doesn’t need a separate operating system like a full virtual machine, so containers are light and start quickly. On AWS, images are stored in ECR, and containers are run with ECS, EKS or Fargate.
Simple example
Section titled “Simple example”A ship’s shipping container. Whatever is inside, the outside size is the same — so it can be loaded onto any ship, at any port. A software container likewise runs the same way anywhere.
Why it’s needed
Section titled “Why it’s needed”It solves the “but it worked on my computer!” problem. The same container runs the same way on a developer’s laptop, a test server and the real server.
Where it’s used
Section titled “Where it’s used”Web apps, APIs and background jobs. Docker is the most popular tool for building and running containers.
Key terms
Section titled “Key terms”| English | Simple meaning |
|---|---|
| Image | The mould or recipe for a container |
| Container | The thing that runs from an image |
| Registry | A store for keeping images |
Azure equivalent
Section titled “Azure equivalent”Containers are the same thing in Azure (Docker containers)
Related
Section titled “Related”Amazon ECR · Amazon ECS · What is Kubernetes?
Learn more
Section titled “Learn more”For details and the latest information, see the official documentation: