AWS CLOUD CERTIFICATIONS
AWS Core Services Overview: EC2, S3, RDS, Lambda, VPC & More
Have too many AWS services in your head and not sure which of them you need for your exam? The bright side is that CLF-C02 is geared towards a manageable core set. This guide explains the fundamentals of the core services (EC2, S3, RDS, Lambda, VPC, and more) in simple terms — what they do and why they're tested.
Quick Answers
AWS Cloud Technology and Services is the most heavily weighted section of the CLF-C02 exam (approx. 34%) – Compute (EC2, Lambda), Storage (S3, EBS), Databases (RDS, DynamoDB), Networking (VPC). Don't worry about being an expert in each service, the exam will check your knowledge of what each service does, when to use each service and how it can be used in a simple cloud setup. In this way, it's best to start with these core services and get them working before looking through AWS's wider service catalog.
Key Takeaways
EC2 and Lambda are two different compute options: server based and serverless.
Object storage versus block storage attached to an instance are different storage problems, solved by S3 and EBS, respectively.
RDS and DynamoDB are two kinds of database services: relational and NoSQL, respectively.
VPC is the backbone of networking that separates and protects AWS resources.
The exam is based on conceptual questions and 'use-cases' matching, not on hands-on configuration.
Compute and Storage Services Explained.
Compute services are what your applications run on. Amazon EC2 (Elastic Compute Cloud) provides you with virtual servers that you can fully control, perfect for applications that require long running compute power. With AWS Lambda, the code is uploaded and AWS only runs it when triggered, charging you only for time spent running, which is well suited for short, event-driven tasks. Storage services are split in a similar fashion, with Amazon S3 (Simple Storage Service), delivering object storage for storing files, backups and storing the contents of static websites on a massive scale, whereas Amazon EBS (Elastic Block Storage) delivers persistent block storage directly attached to an EC2 instance, akin to a virtual hard drive. One of the most common conceptual areas that is tested in CLF-C02 is understanding the compute-and-storage pairing, when to use a server and when to use serverless, and object storage versus block storage.
This course introduces students to the concepts and principles of databases and networking.
AWS databases can be divided into relational and non-relational databases. Amazon RDS (Relational Database Service) is used to run traditional SQL databases such as MySQL or PostgreSQL; it will back up, patch, and scale your database for you, and is suited for structured data that has well defined relationships. Amazon DynamoDB, which is a fully managed NoSQL database, however, was designed for high throughput applications that require flexibility in their schema, such as gaming leaderboards, or IoT data where schema is not required. Networking connects everything together with Amazon VPC (Virtual Private Cloud), which enables you to build an isolated and customisable network in AWS to manage resource communication with the internet and resources. The exam questions often involve determining whether a database type is appropriate for a specific use case or why a VPC is important for security and resource isolation.
Skills Needed to Understand Core AWS Services
Matching compute options (EC2 vs. Lambda) to appropriate business use cases
Distinguishing between different types of data storage (S3 vs. EBS) by data access patterns
Relational (RDS) vs NoSQL (DynamoDB) databases
Knowing the fundamental concepts of VPC such as subnets, security groups, and isolation
Relating individual services together in a coherent, simple cloud architecture
Core AWS Services Covered in CLF-C02
Services at a Glance
| Service | Category | Primary Use Case |
|---|---|---|
| Amazon EC2 | Compute | Virtual servers for long-running applications |
| AWS Lambda | Compute (Serverless) | Event-driven code execution without managing servers |
| Amazon S3 | Storage | Object storage for files, backups, and static content |
| Amazon EBS | Storage | Persistent block storage attached to EC2 instances |
| Amazon RDS | Database | Managed relational (SQL) databases |
| Amazon DynamoDB | Database | Managed NoSQL database for flexible, high-speed data |
| Amazon VPC | Networking | Isolated, customizable network environment |
Step-by-Step Roadmap to Learning Core Services
Begin with compute services: Get to know EC2 first and compare with Lambda.
Switch to storage - know about S3 for objects, EBS for block storage for instances.
Understand that Relational Data Service (RDS) allows for study databases, while DynamoDB is based on a NoSQL paradigm.
Customize and understand VPC basics such as subnets, security groups, and resource communication.
Try hands-on with AWS Free Tier by launching an EC2 instance and creating an S3 bucket.
Assess and test your knowledge with topic-wise quizzes just on Cloud Technology and Services.
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Expert Insights
“The mentors, observing candidate performance on a regular basis, state that they find that candidates get the Cloud Technology and Services domain wrong not because of its complexity, but because candidates can just regurgitate the names of services without understanding their purpose. Even 20–30 minutes per service of hands-on experience in the AWS Free Tier gives you intuition that you can't get from pure reading!