AWS CLF-C02: Cloud Concepts Practice Questions

Elasticity is the ability to automatically scale resources up during demand spikes and scale down during quiet periods, perfectly matching the news platform's variable traffic pattern and avoiding both over-provisioning and under-provisioning. Global reach refers to the ability to deploy workloads in multiple geographic locations worldwide, not traffic scaling. Agility refers to how quickly developers can experiment and deploy new resources (speed of innovation), not auto-scaling of capacity. Fault tolerance refers to the ability to continue operating despite component failures, not to matching capacity with demand.

Amazon EC2 is IaaS because it provides raw virtualized compute infrastructure that the customer manages (OS, runtime, applications). AWS Elastic Beanstalk is PaaS because it abstracts infrastructure management and lets developers deploy applications without managing servers. Microsoft 365 is SaaS because it delivers fully managed software directly to end users via the internet with no infrastructure or platform management required. The other options incorrectly map these services to the wrong models.

Economies of scale describes how AWS can reduce per-unit costs and pass those savings to customers as it grows its massive infrastructure and customer base — fixed costs (data centers, hardware, networking) are spread across millions of customers. Pay-as-you-go pricing refers to the billing model where you pay only for what you consume, not the reason why costs decrease over time. Reserved capacity discounts are a purchasing option for committed usage, not an explanation for why AWS can offer lower prices. Elasticity is the ability to scale resources dynamically, unrelated to the economics of why AWS can charge less.

Edge Locations are the geographically distributed points of presence used by Amazon CloudFront (and other AWS services like Route 53) to cache and serve content closer to end users, reducing latency. There are many more Edge Locations worldwide than Regions or AZs. Availability Zones are isolated data centers within a Region used to host workloads, not to serve cached content. AWS Local Zones extend AWS infrastructure to metro areas for ultra-low-latency compute, but are not the caching locations used by CloudFront. AWS Outposts are fully managed AWS infrastructure deployed in a customer's on-premises data center.

Reliability is the Well-Architected Framework pillar focused on a workload's ability to perform its intended function correctly and consistently, and to recover from failures. Operational Excellence focuses on running and monitoring systems to deliver business value and continually improving processes. Performance Efficiency focuses on using computing resources efficiently to meet requirements and maintaining that efficiency as demand changes. Security focuses on protecting information, systems, and assets through risk assessments and mitigation strategies.