AWS Certified Cloud Practitioner 1-10

AWS CloudTrail is a service that records user activity and API calls within an AWS account, enabling governance and auditing.
Because it can track the history of events such as launching, stopping, terminating, and rebooting EC2 instances, it is well suited for reviewing what happened to an instance that has disappeared from the list.
Cost Explorer is a tool for visualizing cost and usage, Amazon Inspector is a vulnerability assessment service, and AWS Secrets Manager is a service for managing sensitive information—none of which can be used to track API event history.
When you want to track API operations or change history on a resource after the fact, choose AWS CloudTrail—this is the key point for the exam.
AWS CloudTrail User Guide

AWS Backup is a fully managed service that lets you centrally manage backup operations across multiple AWS services.
You create a backup plan that defines backup frequency, retention period, and lifecycle, and apply it collectively to target resources using tags or resource IDs.
It supports a wide range of services, including Amazon EC2, EBS, RDS, DynamoDB, EFS, FSx, and Storage Gateway.
AWS Batch runs batch processing, AWS Elastic Disaster Recovery handles disaster recovery, and Amazon FSx is a file storage service—none of which are for defining a centralized data protection policy.
When you want to centrally manage backups across multiple services, choose AWS Backup—remember this.
What Is AWS Backup

Amazon SQS provides fully managed message queues and enables asynchronous communication between microservices.
By decoupling the sender and receiver (loose coupling), messages are retained in the queue even if one side is down, preventing message loss.
Elastic Load Balancing distributes traffic across multiple targets, Amazon SNS is a pub/sub push notification service, and Amazon CloudFront is a content delivery network (CDN).
It is important to distinguish queue-based loose coupling and asynchronous messaging as Amazon SQS, and push-based pub/sub as Amazon SNS.
What Is Amazon SQS

Savings Plans is a pricing model that discounts compute costs for EC2, Fargate, Lambda, and others in exchange for committing to a consistent amount of usage (an hourly spend amount) over a one-year or three-year term.
Amazon Detective is a security investigation service, AWS Pricing is a term referring to the pricing structure itself, and Basic Support is a free support plan—none of which provide discounts in exchange for a spend commitment.
Discounts in exchange for a usage commitment are typified by Savings Plans (and Reserved Instances)—remember this.
What Is Savings Plans

Amazon EFS (Elastic File System) is a fully managed shared file storage that can be mounted and read from/written to simultaneously by multiple EC2 instances.
It supports the NFSv4 protocol and automatically scales its capacity up and down as demand changes.
Amazon EBS is block storage that is, in principle, attached to a single instance, Amazon S3 is object storage, and AWS Artifact is a service for obtaining compliance-related documents.
When you need a shared file system accessed simultaneously by multiple EC2 instances, choose Amazon EFS—this is the key point.
What Is Amazon Elastic File System

Under the AWS shared responsibility model, AWS is responsible for “security of the cloud,” and the customer is responsible for “security in the cloud.”
AWS manages the physical security of facilities, hardware, the underlying infrastructure, and the foundational portions of managed services.
Meanwhile, the customer is responsible for configuring security groups and network ACLs, encrypting customer data, managing access with IAM, and so on.
Option A is AWS’s responsibility, and the Lambda infrastructure in D and the Region network throughput in E are also managed by AWS.
Be sure to grasp that configuring security groups and encrypting data are the customer’s responsibility.
AWS Shared Responsibility Model

VPC peering privately connects two VPCs one-to-one and can route traffic between them without going over the internet.
However, it does not support transitive connectivity (automatic connectivity among A-B-C).
AWS Transit Gateway connects many VPCs and on-premises networks to a central hub, centrally manages routing, and also supports transitive routing.
VPC endpoints provide private connectivity to AWS services, Amazon Route 53 is DNS, and AWS Direct Connect is a dedicated line connection to on-premises—none of which are for directly connecting VPCs to each other.
Connecting VPCs to each other is done with VPC peering or AWS Transit Gateway—remember this.
What Is VPC Peering

AWS Budgets is a service that lets you set your own budgets for cost and usage and receive notifications when a threshold is exceeded.
Because it aggregates and reports past and current-month cost and usage data and can periodically and automatically generate budget reports, it is well suited for tracking actuals for quarterly planning.
Amazon Detective is a security investigation service, AWS Pricing Calculator is a tool for upfront estimates, and AWS Savings Plans is a discount pricing model—none of which are for tracking actual data or automatically generating reports.
Setting budgets, receiving overage notifications, and generating actuals-tracking reports are the key points of AWS Budgets.
Managing Costs with AWS Budgets

Amazon CloudFront is a content delivery network (CDN) that caches content at edge locations placed around the world.
By delivering content from the edge location closest to the user, it achieves low-latency, high-speed access.
Amazon Route 53 is a DNS service; it performs name resolution and routing but does not cache content.
Elastic Load Balancing distributes traffic, and AWS Lambda is serverless compute—neither is for global content delivery itself.
Global low-latency delivery and caching is the key point of Amazon CloudFront (CDN).
What Is Amazon CloudFront

AWS CodePipeline is a continuous delivery / continuous deployment (CI/CD) orchestration service that automates each stage of the release process, such as retrieving source code, building, testing, and deploying.
AWS AppSync is a GraphQL API, AWS Cloud9 is a cloud integrated development environment (IDE), and AWS CodeCommit is a Git-based source code repository—all of which relate to application development, but the one that automates the entire release pipeline is CodePipeline.
CI/CD pipeline automation is handled by AWS CodePipeline—remember this.
What Is AWS CodePipeline