Top 50 Most Asked AWS Questions (With Answers)

9 June 2025
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Introduction

Whether you're preparing for an AWS certification, a job interview, or simply looking to expand your cloud knowledge, understanding the most commonly asked AWS questions is essential in today's tech landscape. At DevOps Horizon, we've compiled the top 50 AWS questions you're likely to encounter, complete with straightforward answers to help boost your cloud expertise.

Fundamental AWS Concepts

1. What is AWS?

Amazon Web Services (AWS) is a comprehensive cloud platform offering over 200 fully-featured services from data centers globally. It provides infrastructure as a service (IaaS), platform as a service (PaaS), and packaged software as a service (SaaS) offerings.

2. What are the key advantages of using AWS?

Pay-as-you-go pricing (no upfront costs)
Scalability and elasticity
Global infrastructure
High availability and reliability
Comprehensive security features
Wide range of services for various use cases

3. What is the AWS shared responsibility model?

The shared responsibility model divides security responsibilities between AWS and the customer. AWS is responsible for "security of the cloud" (infrastructure, hardware, software), while customers are responsible for "security in the cloud" (data, configurations, access management).

4. What is a region in AWS?

A region is a physical location around the world where AWS clusters data centers. Each region is completely independent and isolated from other regions, containing multiple Availability Zones.

5. What is an Availability Zone (AZ)?

An Availability Zone is one or more discrete data centers with redundant power, networking, and connectivity in an AWS Region. AZs are physically separated to isolate from failures in other AZs.

Compute Services

6. What is EC2?

Amazon Elastic Compute Cloud (EC2) provides resizable compute capacity in the cloud. It allows you to run virtual servers (instances) for various workloads with different instance types optimized for different use cases.

7. What are the different EC2 instance purchasing options?

On-Demand Instances: Pay by the hour with no long-term commitments
Reserved Instances: Up to 72% discount for 1-3 year commitments
Spot Instances: Up to 90% discount for unused EC2 capacity
Dedicated Hosts: Physical EC2 servers dedicated for your use
Savings Plans: Flexible pricing model with commitment to a consistent amount of usage

8. What is Auto Scaling?

AWS Auto Scaling monitors applications and automatically adjusts capacity to maintain steady, predictable performance at the lowest possible cost. It adds or removes EC2 instances based on demand.

9. What is an AMI?

An Amazon Machine Image (AMI) provides the information required to launch an EC2 instance. It includes the root volume for the instance, launch permissions, and block device mappings.

10. What is AWS Lambda?

AWS Lambda is a serverless compute service that runs code in response to events and automatically manages the underlying compute resources. You pay only for the compute time consumed.

Storage Services

11. What is Amazon S3?

Amazon Simple Storage Service (S3) is an object storage service offering industry-leading scalability, data availability, security, and performance. It can store and retrieve any amount of data from anywhere.

12. What are S3 storage classes?

S3 Standard: General-purpose storage for frequently accessed data
S3 Intelligent-Tiering: Automatic cost optimization for data with unknown or changing access patterns
S3 Standard-IA: For infrequently accessed data with rapid access when needed
S3 One Zone-IA: For infrequently accessed data that doesn't require multi-AZ resilience
S3 Glacier: Low-cost archival storage with retrieval times from minutes to hours
S3 Glacier Deep Archive: Lowest-cost storage for long-term archiving with retrieval times of 12 hours

13. What is Amazon EBS?

Amazon Elastic Block Store (EBS) provides persistent block storage volumes for use with EC2 instances. EBS volumes remain independent from the instance lifecycle and can be attached to any instance in the same Availability Zone.

14. What is Amazon EFS?

Amazon Elastic File System (EFS) provides a simple, scalable, elastic file system for Linux-based workloads. It can be used with AWS cloud services and on-premises resources and scales automatically as files are added or removed.

15. What is AWS Storage Gateway?

AWS Storage Gateway is a hybrid cloud storage service that connects on-premises environments with cloud storage. It provides seamless integration between on-premises applications and AWS storage.

Database Services

16. What is Amazon RDS?

Amazon Relational Database Service (RDS) makes it easy to set up, operate, and scale a relational database in the cloud. It provides cost-efficient and resizable capacity while automating time-consuming administration tasks.

17. What database engines does RDS support?

RDS supports multiple database engines, including:

Amazon Aurora
PostgreSQL
MySQL
MariaDB
Oracle Database
SQL Server

18. What is DynamoDB?

Amazon DynamoDB is a fully managed NoSQL database service that provides fast and predictable performance with seamless scalability. It's a key-value and document database with single-digit millisecond performance.

19. What is Amazon Redshift?

Amazon Redshift is a fully managed, petabyte-scale data warehouse service in the cloud. It's designed for analyzing all your data using your existing business intelligence tools.

20. What is Amazon Aurora?

Amazon Aurora is a MySQL and PostgreSQL-compatible relational database built for the cloud. It combines the performance and availability of traditional enterprise databases with the simplicity and cost-effectiveness of open-source databases.

Networking & Content Delivery

21. What is Amazon VPC?

Amazon Virtual Private Cloud (VPC) lets you provision a logically isolated section of the AWS Cloud where you can launch resources in a virtual network that you define. You have complete control over your networking environment.

22. What are security groups in AWS?

Security groups act as virtual firewalls for EC2 instances to control inbound and outbound traffic. They operate at the instance level and can specify allow rules but not deny rules.

23. What is a Network ACL?

A network access control list (NACL) is an optional layer of security for your VPC that acts as a firewall for controlling traffic in and out of one or more subnets. NACLs can have both allow and deny rules.

24. What is AWS Direct Connect?

AWS Direct Connect is a cloud service that establishes a dedicated network connection from your premises to AWS, providing more consistent network performance and potentially reducing network costs.

25. What is Amazon CloudFront?

Amazon CloudFront is a fast content delivery network (CDN) service that securely delivers data, videos, applications, and APIs to customers globally with low latency and high transfer speeds.

Security, Identity & Compliance

26. What is IAM?

AWS Identity and Access Management (IAM) enables you to securely control access to AWS services and resources. It helps you create and manage AWS users and groups and use permissions to allow or deny their access to resources.

27. What are IAM roles?

IAM roles are entities with specific permission policies that determine what actions an entity can perform in AWS. Roles can be assumed by trusted entities such as AWS services, applications, or users.

28. What is AWS KMS?

AWS Key Management Service (KMS) makes it easy to create and manage cryptographic keys and control their use across a wide range of AWS services and in your applications.

29. What is AWS WAF?

AWS Web Application Firewall (WAF) helps protect your web applications from common web exploits that could affect application availability, compromise security, or consume excessive resources.

30. What is Amazon GuardDuty?

Amazon GuardDuty is a threat detection service that continuously monitors for malicious activity and unauthorized behavior to protect your AWS accounts, workloads, and data.

Management & Monitoring

31. What is Amazon CloudWatch?

Amazon CloudWatch is a monitoring and observability service that provides data and actionable insights for AWS, hybrid, and on-premises applications and infrastructure resources.

32. What is AWS CloudTrail?

AWS CloudTrail is a service that enables governance, compliance, operational auditing, and risk auditing of your AWS account. It logs, continuously monitors, and retains account activity related to actions across your AWS infrastructure.

33. What is AWS Config?

AWS Config is a service that enables you to assess, audit, and evaluate the configurations of your AWS resources. It continuously monitors and records your AWS resource configurations.

34. What is AWS Systems Manager?

AWS Systems Manager provides a unified interface for viewing operational data from multiple AWS services and automates operational tasks across your AWS resources.

35. What is AWS Trusted Advisor?

AWS Trusted Advisor is an online tool that provides real-time guidance to help you provision your resources following AWS best practices in areas like cost optimization, security, fault tolerance, and performance improvement.

Serverless & Application Services

36. What is AWS API Gateway?

Amazon API Gateway is a fully managed service that makes it easy for developers to create, publish, maintain, monitor, and secure APIs at any scale.

37. What is AWS Step Functions?

AWS Step Functions is a serverless orchestration service that lets you combine AWS Lambda functions and other AWS services to build business-critical applications.

38. What is Amazon SQS?

Amazon Simple Queue Service (SQS) is a fully managed message queuing service that enables you to decouple and scale microservices, distributed systems, and serverless applications.

39. What is Amazon SNS?

Amazon Simple Notification Service (SNS) is a fully managed messaging service for both application-to-application (A2A) and application-to-person (A2P) communication.

40. What is Amazon EventBridge?

Amazon EventBridge is a serverless event bus that makes it easy to connect applications together using data from your own applications, SaaS applications, and AWS services.

Containers & Orchestration

41. What is Amazon ECS?

Amazon Elastic Container Service (ECS) is a fully managed container orchestration service that helps you run, stop, and manage Docker containers on a cluster.

42. What is Amazon EKS?

Amazon Elastic Kubernetes Service (EKS) is a managed service that makes it easy for you to run Kubernetes on AWS without needing to install and operate your own Kubernetes control plane.

43. What is AWS Fargate?

AWS Fargate is a serverless compute engine for containers that works with both Amazon ECS and Amazon EKS. It lets you run containers without having to manage servers or clusters.

44. What is Amazon ECR?

Amazon Elastic Container Registry (ECR) is a fully managed Docker container registry that makes it easy to store, manage, and deploy Docker container images.

45. What is the difference between ECS and EKS?

ECS is AWS's proprietary container orchestration platform, while EKS is a managed Kubernetes service. ECS is easier to use for AWS-centric workloads, while EKS offers greater portability and a larger ecosystem.

Migration & Hybrid Cloud

46. What is AWS Migration Hub?

AWS Migration Hub provides a single location to track the progress of application migrations across multiple AWS and partner solutions.

47. What is AWS Outposts?

AWS Outposts is a fully managed service that extends AWS infrastructure, services, APIs, and tools to virtually any data center, co-location space, or on-premises facility.

48. What is AWS Storage Gateway?

AWS Storage Gateway is a hybrid cloud storage service that gives you on-premises access to virtually unlimited cloud storage.

49. What is AWS Snowball?

AWS Snowball is a petabyte-scale data transport solution that uses secure appliances to transfer large amounts of data into and out of AWS.

50. What is AWS Cloud Development Kit (CDK)?

AWS CDK is an open-source software development framework to define cloud infrastructure in code and provision it through AWS CloudFormation.

Conclusion

Mastering these top 50 AWS questions provides a solid foundation for working with AWS services. Whether you're preparing for certification exams or looking to enhance your cloud skills for career advancement, understanding these concepts is essential in today's cloud-first world.

At DevOps Horizon, we offer comprehensive training to help you deepen your AWS knowledge and prepare for certifications. Check out our AWS certification prep guides and practical how-to tutorials to continue your cloud learning journey.

Ready to take your AWS skills to the next level? Explore our blog for more in-depth articles and tutorials on AWS, Azure, Terraform, and other DevOps technologies.