1. What is Docker?
Docker is a tool that lets you package an application and everything it needs into a container.
This ensures the app runs the same way on any machine.
2. What problem does Docker solve?
Docker eliminates the “it works on my machine” problem. It creates a consistent environment across development, testing, and production.
3. What is a container?
A container is a lightweight, isolated environment that runs an application. It shares the host OS but includes its own dependencies and configuration.
4. How is Docker different from a virtual machine?
Virtual machines include a full operating system, making them heavy. Docker containers are lighter because they share the host OS kernel.
5. What is Kubernetes?
Kubernetes is a container orchestration platform. It manages, scales, and keeps containers running automatically.
6. Why was Kubernetes created?
Kubernetes was created to manage containers at scale. Running many containers manually becomes complex and error-prone.
7. Docker vs Kubernetes: what’s the main difference?
Docker creates and runs containers. Kubernetes manages and orchestrates many containers across servers.
8. Do Docker and Kubernetes compete?
No, they work together rather than compete. Docker builds containers, Kubernetes runs and manages them.
9. Is Kubernetes a replacement for Docker?
No, Kubernetes does not replace Docker. It relies on containers created by Docker or other container tools.
10. Can you use Docker without Kubernetes?
Yes, many applications run perfectly using Docker alone. Small projects often don’t need Kubernetes at all.
11. Can you use Kubernetes without Docker?
Yes, Kubernetes supports other container runtimes. Docker is common, but not the only option.
12. When should you use Docker only?
Docker alone is great for small apps and local development. It’s also ideal when scaling and high availability aren’t critical.
13. When should you use Kubernetes?
Kubernetes makes sense when you run many containers in production. It helps with scaling, self-healing, and deployment automation.
14. Is Kubernetes overkill for beginners?
Often yes, especially for learning or small apps. Docker provides a simpler and faster starting point.
15. Is Kubernetes hard to learn?
Kubernetes has a steep learning curve. It introduces many new concepts like pods, services, and clusters.
16. Should beginners learn Docker or Kubernetes first?
Beginners should start with Docker. Understanding containers is essential before learning Kubernetes.
17. What is a Kubernetes cluster?
A cluster is a group of machines running Kubernetes. It includes worker nodes and a control plane.
18. What is a Kubernetes pod?
A pod is the smallest deployable unit in Kubernetes. It can contain one or more containers that share resources.
19. What is container orchestration?
Container orchestration automates deployment and management. It handles scaling, networking, and container failures.
20. How does Kubernetes handle scaling?
Kubernetes can automatically add or remove containers. This is based on traffic or resource usage.
21. What happens if a container crashes in Docker?
Docker stops the container unless restart rules are configured. Recovery is mostly manual.
22. What happens if a container crashes in Kubernetes?
Kubernetes automatically restarts or replaces the container. This improves application reliability.
23. How does Kubernetes improve reliability?
It continuously monitors container health. If something fails, Kubernetes fixes it automatically.
24. What is Docker Compose?
Docker Compose lets you run multiple containers together. It’s useful for local development and simple setups.
25. Docker Compose vs Kubernetes?
Docker Compose is simpler and local-focused. Kubernetes is production-grade and highly scalable.
26. Is Docker enough for production?
Yes, for small or medium applications. Many companies successfully run production apps using Docker alone.
27. Why is Kubernetes popular in production?
It automates scaling, healing, and deployments. This reduces downtime and manual work.
28. How do deployments work in Docker?
Deployments are usually manual or script-based. Rolling updates require custom setup.
29. How do deployments work in Kubernetes?
Kubernetes supports rolling updates out of the box. It allows zero-downtime deployments.
30. What is a Kubernetes service?
A service exposes containers to the network. It provides stable networking even if containers change.
31. How does networking differ in Docker vs Kubernetes?
Docker networking is simple and local. Kubernetes networking is more powerful but complex.
32. How do Docker and Kubernetes handle configuration?
Docker often uses environment variables or files. Kubernetes uses ConfigMaps and Secrets.
33. What are Kubernetes Secrets?
Secrets store sensitive data like passwords. They keep credentials separate from application code.
34. Is Kubernetes secure by default?
Kubernetes provides security features but needs configuration. Misconfigured clusters can be risky.
35. Is Docker secure?
Docker containers are isolated but not fully secure alone. Security depends on proper configuration and image hygiene.
36. What are common Docker mistakes beginners make?
Using large images and running containers as root. Ignoring image versioning is also common.
37. What are common Kubernetes beginner mistakes?
Overusing Kubernetes too early. Not understanding core concepts before deploying.
38. Is Kubernetes expensive?
Kubernetes itself is free. Costs come from cloud infrastructure and operations.
39. Does Docker reduce costs?
Yes, Docker improves resource efficiency. It allows more applications to run on fewer servers.
40. What skills do you need before Kubernetes?
Linux basics, Docker, and networking fundamentals. Cloud knowledge is also very helpful.
41. Can developers use Docker without DevOps?
Yes, developers use Docker daily. It simplifies development and testing workflows.
42. Do all companies use Kubernetes?
No, many companies don’t need it. The tool should match the problem size.
43. What is self-healing in Kubernetes?
Kubernetes detects failures automatically. It restarts or replaces broken containers.
44. What is auto-scaling?
Auto-scaling adjusts container count automatically. It responds to traffic or CPU usage.
45. Is Kubernetes required for microservices?
No, but it helps manage microservices at scale. Smaller systems may not need it.
46. How long does it take to learn Docker?
Basic Docker can be learned in days. Advanced usage takes practice.
47. How long does it take to learn Kubernetes?
Basic concepts take weeks. Real-world mastery can take months.
48. What is the biggest advantage of Docker?
Simplicity and consistency across environments. It makes development and deployment faster.
49. What is the biggest advantage of Kubernetes?
Automation at scale. It reduces operational effort in large systems.
50. Docker vs Kubernetes: which should I choose?
Choose Docker for simplicity and learning. Choose Kubernetes when scale and reliability demand it.
Conclusion.
Docker and Kubernetes are powerful tools, but they solve different problems. Docker focuses on creating and running containers, making applications easy to build, ship, and run consistently across environments. For beginners, Docker alone is often more than enough and provides the foundation needed to understand containerized applications.
Kubernetes comes into play when applications grow in size and complexity. It automates deployment, scaling, and recovery of containers, which is especially valuable in production environments with high availability needs. However, its added power also brings added complexity, making it something best approached after learning Docker basics.
For beginners, the key takeaway is simple: start with Docker, then move to Kubernetes when you truly need it. Understanding when and why to use each tool will help you avoid unnecessary complexity while building reliable, scalable applications at the right pace.
For more information about Kubernetes and Docker, you can refer to Jeevi’s page.
This tutorial is just the beginning learn Kubernetes hands-on in our complete course. Upgrade your skills with AWS.
