Basic Concepts and Services

1. What is AWS?
   • Answer: Amazon Web Services (AWS) is a comprehensive cloud computing platform provided by Amazon. It offers a range of cloud services including computing power, storage, and databases, allowing users to scale and manage applications more efficiently.
2. What is EC2 in AWS?
   • Answer: Amazon Elastic Compute Cloud (EC2) provides scalable virtual servers in the cloud. Users can launch, manage, and terminate instances (virtual machines) as needed.
3. What is S3?
   • Answer: Amazon Simple Storage Service (S3) is an object storage service that offers highly durable, scalable, and secure storage for a variety of data types, such as documents, images, and backups.
4. What is the purpose of IAM in AWS?
   • Answer: AWS Identity and Access Management (IAM) allows users to manage access to AWS services and resources securely. It enables the creation of users, groups, and roles, and defines permissions using policies.
5. What is the difference between EC2 and Lambda?
   • Answer: EC2 provides scalable virtual servers for running applications, while AWS Lambda is a serverless computing service that executes code in response to events without provisioning or managing servers.
6. What is AWS RDS?
   • Answer: Amazon Relational Database Service (RDS) is a managed database service that supports several database engines, including MySQL, PostgreSQL, MariaDB, Oracle, and SQL Server. It handles routine database tasks like backups, patching, and scaling.
7. What is CloudFormation?
   • Answer: AWS CloudFormation is a service that allows users to define and provision AWS infrastructure using code. It uses templates written in JSON or YAML to describe and automate the setup of resources.
8. What is the difference between S3 and EBS?
   • Answer: Amazon S3 is an object storage service used for storing large amounts of unstructured data, while Amazon EBS (Elastic Block Store) provides block storage for use with EC2 instances, suitable for data that requires frequent updates.
9. What is AWS VPC?
   • Answer: Amazon Virtual Private Cloud (VPC) allows users to create isolated networks within the AWS cloud. Users can define IP address ranges, create subnets, and configure routing and security settings.
10. What is Elastic Load Balancer (ELB)?
    • Answer: Amazon Elastic Load Balancer (ELB) distributes incoming application traffic across multiple EC2 instances to ensure high availability and fault tolerance.

Networking and Security

11. What is a security group in AWS?
    • Answer: A security group acts as a virtual firewall for EC2 instances, controlling inbound and outbound traffic based on defined rules.
12. What is the purpose of AWS Route 53?
    • Answer: Amazon Route 53 is a scalable Domain Name System (DNS) web service that provides DNS routing, domain registration, and health checking for applications.
13. What is a Network ACL (NACL)?
    • Answer: Network Access Control Lists (NACLs) provide an additional layer of security for VPCs. They control inbound and outbound traffic at the subnet level.
14. How does AWS handle encryption?
    • Answer: AWS provides several encryption options, including server-side encryption for S3 and EBS, as well as encryption in transit using SSL/TLS. Users can also manage their encryption keys using AWS Key Management Service (KMS).
15. What is AWS Direct Connect?
    • Answer: AWS Direct Connect is a service that provides a dedicated network connection between your on-premises data center and AWS, improving bandwidth and reducing network costs.

Storage and Databases

16. What is Amazon Glacier?
    • Answer: Amazon Glacier is a low-cost, long-term archival storage service designed for data that is infrequently accessed but needs to be retained for long periods.
17. What is Amazon DynamoDB?
    • Answer: Amazon DynamoDB is a fully managed NoSQL database service that provides fast and predictable performance with seamless scalability. It supports both document and key-value data models.
18. How does AWS handle database backups?
    • Answer: AWS provides automated backups for RDS, with the option to configure backup retention periods and perform manual snapshots. For DynamoDB, users can enable on-demand backups and point-in-time recovery.
19. What is the purpose of AWS EFS?
    • Answer: Amazon Elastic File System (EFS) provides a scalable and managed file storage service for use with EC2 instances. It supports shared access and is ideal for applications requiring a file system interface.
20. What is the difference between Amazon RDS and Amazon Redshift?
    • Answer: Amazon RDS is a managed relational database service suitable for transactional workloads, while Amazon Redshift is a fully managed data warehouse service designed for large-scale data analytics and complex queries.

Compute and Serverless

21. What are AWS Lambda functions?
    • Answer: AWS Lambda functions are serverless compute resources that execute code in response to events without provisioning or managing servers. They automatically scale based on the number of events.
22. How do you configure auto-scaling for EC2 instances?
    • Answer: Configure auto-scaling using AWS Auto Scaling groups. Define scaling policies and thresholds to automatically adjust the number of EC2 instances based on traffic or load.
23. What is Amazon ECS?
    • Answer: Amazon Elastic Container Service (ECS) is a fully managed container orchestration service that supports Docker containers and allows you to run and scale containerized applications on AWS.
24. What is Amazon EKS?
    • Answer: Amazon Elastic Kubernetes Service (EKS) is a managed Kubernetes service that simplifies the process of running Kubernetes clusters on AWS, handling the control plane and management tasks.
25. What is AWS Fargate?
    • Answer: AWS Fargate is a serverless compute engine for containers that works with both Amazon ECS and EKS. It allows you to run containers without managing the underlying infrastructure.

Monitoring and Management

26. What is Amazon CloudWatch?
    • Answer: Amazon CloudWatch is a monitoring and management service that provides data and insights into AWS resources and applications. It offers metrics, logs, and alarms to help manage and optimize performance.
27. What is AWS CloudTrail?
    • Answer: AWS CloudTrail is a service that provides governance, compliance, and auditing by recording API calls made on your account. It helps track user activity and API usage.
28. How do you use AWS CloudFormation?
    • Answer: Use AWS CloudFormation to define and provision AWS infrastructure using code. Create templates in JSON or YAML to automate the setup and management of AWS resources.
29. What is the AWS Management Console?
    • Answer: The AWS Management Console is a web-based interface for accessing and managing AWS services. It provides a graphical user interface for performing various tasks and managing resources.
30. What is AWS Trusted Advisor?
    • Answer: AWS Trusted Advisor is a service that provides real-time guidance to help you provision your resources following AWS best practices. It evaluates your AWS environment and makes recommendations for cost optimization, security, and performance.

Networking and Load Balancing

31. What is AWS Elastic Beanstalk?
    • Answer: AWS Elastic Beanstalk is a platform-as-a-service (PaaS) that simplifies the deployment and management of applications by handling infrastructure provisioning, load balancing, scaling, and monitoring.
32. How do you secure access to AWS services?
    • Answer: Secure access using IAM policies, security groups, network ACLs, VPCs, encryption, and multi-factor authentication (MFA). Regularly review and audit permissions and access controls.
33. What is Amazon Route 53 used for?
    • Answer: Amazon Route 53 is a scalable DNS and domain name registration service that provides routing policies, health checks, and domain management features for applications.
34. What is AWS WAF?
    • Answer: AWS Web Application Firewall (WAF) is a security service that helps protect web applications from common web exploits and attacks by allowing users to create custom rules to filter and monitor HTTP/HTTPS requests.
35. What is AWS Shield?
    • Answer: AWS Shield is a managed Distributed Denial of Service (DDoS) protection service that safeguards applications against DDoS attacks. Shield Standard provides automatic protection, while Shield Advanced offers additional features and 24/7 support.

Advanced Topics

36. What is the AWS Global Infrastructure?
    • Answer: The AWS Global Infrastructure consists of regions and availability zones (AZs) around the world. Each region is a separate geographic area, and each region contains multiple AZs, providing high availability and fault tolerance.
37. How does AWS handle data replication?
    • Answer: AWS provides data replication features such as S3 cross-region replication, RDS multi-AZ deployments, and EBS snapshots to ensure data durability and availability across multiple locations.
38. What is AWS Organizations?
    • Answer: AWS Organizations is a service that allows you to manage multiple AWS accounts centrally. It provides policy-based management, consolidated billing, and service control policies (SCPs) for governance.
39. What is Amazon Aurora?
    • Answer: Amazon Aurora is a fully managed relational database engine compatible with MySQL and PostgreSQL. It is designed for high performance and availability with automated backups and replication.
40. What is AWS Glue?
    • Answer: AWS Glue is a managed ETL (extract, transform, load) service that makes it easy to prepare and transform data for analytics. It includes a data catalog, ETL jobs, and integrated data processing capabilities.

Deployment and Automation

41. What is AWS CodePipeline?
    • Answer: AWS CodePipeline is a continuous integration and continuous delivery (CI/CD) service that automates the build, test, and deployment phases of application development.
42. What is AWS CodeDeploy?
    • Answer: AWS CodeDeploy is a deployment service that automates the deployment of applications to Amazon EC2 instances, Lambda functions, or on-premises servers, ensuring consistent and reliable updates.
43. How do you manage secrets in AWS?
    • Answer: Use AWS Secrets Manager or AWS Systems Manager Parameter Store to securely store and manage sensitive information such as API keys, passwords, and database credentials.
44. What is AWS CodeBuild?
    • Answer: AWS CodeBuild is a fully managed build service that compiles source code, runs tests, and produces build artifacts for deployment in a CI/CD pipeline.
45. How do you use AWS Elastic Beanstalk for application deployment?
    • Answer: Deploy applications to AWS Elastic Beanstalk by uploading your code to the Elastic Beanstalk environment. It handles provisioning, scaling, and monitoring, allowing you to focus on application development.

Cost Management and Optimization

46. What is AWS Cost Explorer?
    • Answer: AWS Cost Explorer is a tool that helps users analyze and visualize their AWS spending. It provides insights into cost trends, usage patterns, and cost allocation for better budgeting and cost management.
47. What is the AWS Free Tier?
    • Answer: The AWS Free Tier provides limited access to a range of AWS services at no cost for a specific period (usually 12 months) or with ongoing free usage limits. It allows new users to explore and try AWS services for free.
48. How do you monitor AWS resource utilization?
    • Answer: Monitor AWS resource utilization using Amazon CloudWatch, which provides metrics, logs, and alarms. You can track usage patterns and set up notifications for resource thresholds.
49. What is AWS Savings Plans?
    • Answer: AWS Savings Plans are flexible pricing plans that offer significant cost savings compared to on-demand pricing. They provide pricing discounts in exchange for a commitment to a certain level of usage over a one- or three-year term.
50. How do you optimize AWS costs?
    • Answer: Optimize AWS costs by analyzing usage with Cost Explorer, implementing Reserved Instances or Savings Plans, optimizing resource allocation, and regularly reviewing and adjusting your resource usage and pricing models.

These questions and answers cover a broad range of AWS topics, from fundamental services and security to advanced management and cost optimization. They should provide a solid foundation for an AWS-related interview.