AWS Certified Cloud Practitioner Cloud Concepts Summary

With the cloud you trade fixed expense for variable expense. Instead of paying a large amount up front for servers and data centers, you pay only for the resources you use.

Wrong choices

• Benefit from massive economies of scale: This is about AWS's large size lowering prices, not about paying only for what you use.
• Increase speed and agility: This is about getting resources faster, not about how you pay.
• Go global in minutes: This is about reaching users in other parts of the world quickly.

In the cloud you can add or remove resources as demand changes, so you stop guessing capacity. You no longer pay for idle servers or run short when traffic grows.

Wrong choices

• Go global in minutes: This is about reaching new countries quickly, not about sizing for demand.
• Benefit from massive economies of scale: This is about lower prices from AWS's size.
• Stop spending money running and maintaining data centers: This is about letting AWS handle the building, power, and hardware.

Elasticity is the ability to add resources when demand rises and remove them when demand falls, often automatically. You pay only for what you use at each moment.

Wrong choices

• High availability: High availability means a system keeps running when a part fails.
• Durability: Durability means stored data is not lost.
• Data residency: Data residency is about which country or Region data is kept in.

Rehost (lift and shift) moves an application to the cloud without changing it. It is often the fastest way to migrate.

Wrong choices

• Replatform: Replatform makes a few changes, such as moving to a managed database.
• Refactor: Refactor changes the design and code of the application.
• Repurchase: Repurchase replaces the application with a different product.

Availability Zones are isolated from each other. Running across multiple Availability Zones means a problem in one zone does not stop the whole application.

Wrong choices

• Run several instances in one Availability Zone: If that one Availability Zone has a problem, all instances are affected.
• Use one larger instance in one Availability Zone: A single instance is a single point of failure.
• Take a daily backup of one instance: Backups help recovery but do not keep the application running during a failure.

Because many customers share AWS, AWS can buy and operate at very large volume. These economies of scale turn into lower pay-as-you-go prices for customers.

Wrong choices

• Trade fixed expense for variable expense: This is about paying as you go instead of paying up front.
• Stop guessing capacity: This is about matching resources to demand.
• Increase speed and agility: This is about getting new resources quickly.

AWS has Regions around the world, so you can deploy an application close to users in other countries quickly. This benefit is called go global in minutes.

Wrong choices

• Benefit from massive economies of scale: This is about lower prices, not about reaching other countries.
• Stop guessing capacity: This is about sizing resources for demand.
• Trade fixed expense for variable expense: This is about how you pay, not where you deploy.

The Security pillar covers protecting information, systems, and assets, for example with access control, encryption, and monitoring.

Wrong choices

• Reliability: Reliability is about recovering from failures and meeting demand.
• Operational excellence: Operational excellence is about running and improving systems day to day.
• Performance efficiency: Performance efficiency is about using computing resources efficiently.

The Sustainability pillar is about reducing energy use and environmental impact, for example by using only the resources you need. It is the sixth pillar of the framework.

Wrong choices

• Cost optimization: Cost optimization is about avoiding unneeded spending.
• Performance efficiency: Performance efficiency is about using resources efficiently to meet requirements.
• Reliability: Reliability is about a workload working correctly and recovering from failures.

The Reliability pillar is about a workload performing its function correctly and consistently, and recovering from failures such as a lost server or network problem.

Wrong choices

• Performance efficiency: Performance efficiency is about using resources efficiently, not recovering from failures.
• Operational excellence: Operational excellence is about running, monitoring, and improving operations.
• Security: Security is about protecting data and systems.