Top 20 AWS Services You MUST Know for the CLF-C02 Exam (2026 Edition)

The AWS Cloud Practitioner (CLF-C02) exam, also known as the AWS CLF-C02, covers essential core services. These services power almost every AWS architecture. While AWS offers more than 200+ services, only a small group appears frequently on the exam.

To score high, you must understand:

• What each service does
• When to use it
• How it fits into AWS architecture
• The business benefit it provides

This guide breaks down the 20 most important AWS services you must know for the CLF-C02 exam. It is written in simple, beginner-friendly language.

Practice real CLF-C02 exam questions here.

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Top 20 Must-Know AWS Services for CLF-C02

These are grouped by category so they’re easier to remember.

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COMPUTE SERVICES

1. Amazon EC2

Virtual servers in the cloud.
Know:

• On-demand vs reserved
• Basic use cases
• Instance types (general idea)

2. AWS Lambda

Run code without servers.
Know:

• Event-driven
• Pay per execution
• No provisioning required

3. Amazon ECS / EKS (Containers)

You don’t need deep knowledge — just know:

• ECS = AWS-managed containers
• EKS = Kubernetes service

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STORAGE SERVICES

4. Amazon S3

Object storage used for nearly everything.

Know:

• Buckets
• Storage classes
• Durability (99.999999999%)
• Common use cases

5. Amazon EBS

Block storage for EC2.

Know the difference vs S3.

6. Amazon EFS

Shared file system for Linux workloads.

Know:

• Auto-scaling
• Multi-AZ shared storage

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DATABASE SERVICES

7. Amazon RDS

Managed relational databases.

Know:

• Backups
• Multi-AZ
• Automated patching

8. Amazon DynamoDB

NoSQL key-value database.

Know:

• Millisecond performance
• Serverless
• Scales automatically

9. Amazon Aurora

High-performance relational engine.

Know:

• Faster than RDS
• Fully managed
• MySQL/PostgreSQL-compatible

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NETWORKING & DELIVERY SERVICES

10. Amazon VPC

Virtual network in AWS.

Know:

• Subnets
• Route tables
• NAT
• Security groups

11. Elastic Load Balancing (ELB)

Distributes traffic across resources.

Know types at a high level:

• ALB
• NLB

12. Amazon CloudFront

Content delivery network.

Know:

• Edge locations
• Latency reduction
• Caching

13. Amazon Route 53

DNS service.

Know:

• Domain registration
• Routing policies

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SECURITY & IDENTITY SERVICES

14. AWS IAM

Identity & access management.

Know:

• Users, roles, groups
• Policies
• MFA
• Least privilege

15. AWS Organizations

Multi-account governance.

Know:

• Consolidated billing
• SCPs (simple concept)

16. AWS Shield & WAF

Protection from attacks.

Know:

• DDoS protection
• Web firewall rules

17. AWS KMS

Encryption key management.

Know:

• Customer-managed keys
• AWS-managed keys

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MANAGEMENT & MONITORING SERVICES

18. Amazon CloudWatch

Monitoring and metrics.

Know:

• Logs
• Alarms
• Dashboards

19. AWS CloudTrail

Tracks API activity and user actions.

Know:

• Audit logs
• Account-level tracking

20. AWS Trusted Advisor

Cost, performance, and security recommendations.

Know the five check categories:

• Cost
• Performance
• Security
• Fault tolerance
• Service limits

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Why These 20 Services Matter the Most

These services form the foundation of almost every exam question. AWS loves asking:

• “Which service would solve this business need?”
• “Which service is most cost-effective?”
• “Which security service prevents ___?”
• “Which database fits this use case?”

If you master these 20 services, you can answer 70–80% of the CLF-C02 exam confidently.

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Study Tip: Learn Services by Use Case, Not by Definition

Example:

• S3 → store images, videos, backups
• Lambda → run code when something happens
• CloudFront → speed up global content delivery
• IAM → control who can do what

AWS exams are scenario-based, so memorize purpose, not syntax.

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Want Practice Questions on These Services?

Get real exam questions here for the exam here.