Cloud Computing AWS Practice Exam

Cloud computing is the on-demand delivery of IT resources over the internet with pay-as-you-go pricing. Instead of owning physical data centers, you rent compute power, storage, and databases from a cloud provider like AWS, Azure, or Google Cloud.

• IaaS (Infrastructure as a Service) — You manage OS, apps, and data; provider manages hardware (e.g., EC2)
• PaaS (Platform as a Service) — Provider manages OS and runtime; you manage code and data (e.g., Elastic Beanstalk)
• SaaS (Software as a Service) — Provider manages everything; you just use the app (e.g., Gmail, Salesforce)

AWS and the customer share security duties:
AWS is responsible for security of the cloud — hardware, networking, facilities, and managed services.
The customer is responsible for security in the cloud — data encryption, IAM policies, OS patching, firewall rules, and application code.

An AWS Region is a geographic area (e.g., us-east-1) containing multiple isolated data centers. An Availability Zone (AZ) is one or more discrete data centers within a Region, each with independent power, networking, and connectivity. Deploying across multiple AZs provides high availability and fault tolerance.

Amazon Elastic Compute Cloud (EC2) provides resizable virtual servers (instances) in the cloud. You choose the instance type, operating system (AMI), storage, and networking configuration. EC2 gives you full control over compute resources with per-second or per-hour billing.