What is Cloud Computing?
Cloud computing is the on-demand delivery of compute power, storage, databases, and other IT resources via the internet. Instead of owning physical hardware, users access these resources from a cloud provider and pay only for what they use.
Three Main Cloud Service Models:
- IaaS (Infrastructure as a Service): Provides virtualized compute, storage, and networking. The customer manages the OS and above. Example: Amazon EC2.
- PaaS (Platform as a Service): Provides a managed platform for deploying applications without managing underlying infrastructure. Example: AWS Elastic Beanstalk.
- SaaS (Software as a Service): Delivers fully managed software over the internet. The provider manages everything. Example: Amazon WorkMail.
Three Main Cloud Deployment Models:
- Public Cloud: Resources are owned and operated by AWS and shared across multiple customers.
- Private Cloud (On-Premises): Resources are hosted within a company's own data center.
- Hybrid Cloud: Combines on-premises infrastructure with public cloud services, connected via services such as AWS Direct Connect or VPN.
Key AWS Global Infrastructure Components:
- Regions: Geographic areas containing multiple, isolated Availability Zones (e.g., us-east-1).
- Availability Zones (AZs): One or more discrete data centers within a Region, designed for fault isolation.
- Edge Locations: Sites used by Amazon CloudFront to cache content closer to end users, reducing latency.
Core AWS Service Categories Tested on CLF-C02:
- Compute: EC2, Lambda, Elastic Beanstalk, ECS, EKS
- Storage: S3, EBS, EFS, S3 Glacier
- Databases: RDS, DynamoDB, Aurora, Redshift
- Networking: VPC, Route 53, CloudFront, Elastic Load Balancing
- Security: IAM, AWS Shield, AWS WAF, AWS KMS
Shared Responsibility Model: AWS is responsible for security of the cloud (hardware, facilities, global infrastructure). Customers are responsible for security in the cloud (data, configurations, access management).
Understanding which services fall under which model and how the global infrastructure is structured are frequently tested areas on the CLF-C02 exam.