Containers come up on the CLF-C02 as a small family of services you have to keep apart: what a container is, and the difference between ECS, EKS and Fargate. None of it requires hands-on experience — just the ability to match a description to the right name.
What a container is
A container packages an application with its dependencies into a lightweight, portable unit that runs the same way everywhere. The exam’s favourite contrast is with a virtual machine: a container shares the host operating system’s kernel and carries only the app, while a VM bundles a full guest OS. That is why containers are lighter and start faster. You choose containers for consistent, portable deployment across environments.
Orchestrators: ECS vs EKS
To run many containers you need an orchestrator, and AWS offers two:
- Amazon ECS — AWS’s own container orchestrator.
- Amazon EKS — managed Kubernetes, the open-source orchestrator, for teams standardising on Kubernetes.
AWS-native versus Kubernetes is the split. If a question names Kubernetes, it is EKS; if it just says “AWS’s container service,” it is ECS.
Launch types: EC2 vs Fargate
Both ECS and EKS need compute to run the containers, and there are two options:
- EC2 launch type — the containers run on EC2 instances you manage.
- AWS Fargate — serverless: AWS runs the compute, so there is no cluster of instances to manage.
Orchestrator (ECS/EKS) is what coordinates the containers; launch type (EC2/Fargate) is what they run on. Fargate is simply the serverless answer to “who manages the servers.”
How to use the questions below
Answer each one before you reveal the explanation, and when you miss, read past the correct letter to why the other three fail. The distractors are always a neighbouring container service — ECS where EKS belongs, or the EC2 launch type described as serverless. Keeping orchestrator and launch type straight is the whole skill, and the reasoning below drills it.
Updated for CLF-C02 (July 2026). The sample questions above are our own work
in the style of the exam — not real exam items. The exam itself is set and marked
by the certification body.