juniorDocker
How do you list running containers and images?
Updated Apr 28, 2026
Short answer
Use docker ps for running containers and docker images for locally stored images.
Deep explanation
Docker leverages Linux namespaces and cgroups to provide isolation. Unlike VMs, there is no hypervisor layer overhead, allowing for near-native performance and rapid startup times.
Real-world example
A developer wants to ensure their app runs exactly the same on their laptop as it does on a colleague's machine.
Common mistakes
- Confusing 'EXPOSE' with port publishing ('-p').
Follow-up questions
- What is a 'layer' in Docker?