Core Services Overview — CLF-C02 practice questions

Practice questions for this topic, with explained answers.

Domain: Cloud Technology and Services ·100 questions · 30 easy · 40 intermediate · 30 hard · page 6 of 7

Question 76 clf-core-services-overview-076

Intermediate · Choose one

A company stores a large set of objects in Amazon S3 but cannot predict how often each object will be accessed, and the pattern changes over time. It wants to reduce storage cost automatically without operational overhead or retrieval charges. Which storage class should it use?

  1. a S3 Intelligent-Tiering
  2. b S3 Standard-Infrequent Access
  3. c S3 One Zone-Infrequent Access
  4. d S3 Glacier Flexible Retrieval
Show answer & explanation

Answer: A

Why A is correct

S3 Intelligent-Tiering automatically moves objects between access tiers based on observed access patterns, with no retrieval fees and no performance impact for the automatic tiers. It is designed exactly for data with unknown, changing, or unpredictable access patterns, in exchange for a small per-object monitoring and automation charge.

Why the others are wrong

  • B — S3 Standard-IA charges a per-GB retrieval fee and has a 30-day minimum storage duration. If objects turn out to be accessed frequently, the retrieval charges can exceed any storage savings.
  • C — S3 One Zone-IA stores data in a single Availability Zone and also charges retrieval fees. It does not adapt to changing access patterns.
  • D — S3 Glacier Flexible Retrieval requires objects to be restored before access, with retrieval times from minutes to hours. That is unsuitable for objects that may be needed immediately.

Last verified: 2026-09-02

Question 77 clf-core-services-overview-077

Intermediate · Choose one

A company wants Amazon S3 to automatically move log objects to a cheaper storage class 30 days after creation and permanently delete them after seven years, with no application code changes. What should be configured?

  1. a An S3 Lifecycle configuration on the bucket
  2. b S3 Cross-Region Replication
  3. c S3 Versioning on the bucket
  4. d An Amazon EventBridge scheduled rule that invokes a custom script
Show answer & explanation

Answer: A

Why A is correct

An S3 Lifecycle configuration is a set of rules that define actions Amazon S3 applies to a group of objects. Transition actions move objects to another storage class after a defined age, and expiration actions delete them. This is a native bucket-level setting that requires no application or scripting changes.

Why the others are wrong

  • B — Cross-Region Replication copies objects to a bucket in another Region for resilience or latency. It neither changes storage class over time nor deletes aged data.
  • C — Versioning preserves multiple variants of an object to protect against accidental overwrite and deletion. It does not transition or expire objects on a schedule by itself.
  • D — A custom scheduled script would work but adds code, permissions, and operational overhead that the built-in lifecycle feature already handles.

Last verified: 2026-09-02

Question 78 clf-core-services-overview-078

Intermediate · Choose one

A company is migrating Windows applications that rely on SMB file shares, NTFS permissions, and Active Directory integration. Which AWS storage service should it use?

  1. a Amazon Elastic Block Store (Amazon EBS)
  2. b Amazon Elastic File System (Amazon EFS)
  3. c Amazon S3 with the AWS CLI sync command
  4. d Amazon FSx for Windows File Server
Show answer & explanation

Answer: D

Why D is correct

Amazon FSx for Windows File Server provides a fully managed native Microsoft Windows file system built on Windows Server. It supports the SMB protocol, NTFS access control lists, Distributed File System namespaces, and integration with AWS Directory Service or a self-managed Active Directory, which is precisely what these applications expect.

Why the others are wrong

  • A — Amazon EBS attaches to one instance at a time and provides block storage, not a shared network file share for multiple Windows servers.
  • B — Amazon EFS uses NFS and is designed for Linux workloads. It does not natively provide SMB shares with NTFS permissions.
  • C — Amazon S3 is object storage. Windows applications that expect a mounted SMB share cannot use it directly.

Last verified: 2026-09-02

Question 79 clf-core-services-overview-079

Intermediate · Choose one

A genomics research team runs high performance computing simulations that require a shared file system delivering sub-millisecond latency and hundreds of gigabytes per second of throughput, with the ability to link to data sets stored in Amazon S3. Which service should they use?

  1. a Amazon FSx for Lustre
  2. b Amazon FSx for Windows File Server
  3. c Amazon S3 accessed directly over HTTPS
  4. d Amazon EFS Standard
Show answer & explanation

Answer: A

Why A is correct

Amazon FSx for Lustre is a fully managed implementation of the Lustre parallel file system, purpose-built for compute-intensive workloads such as high performance computing, machine learning, and genomics. It provides sub-millisecond latency and very high throughput, and it can be linked to an Amazon S3 bucket so that objects appear as files.

Why the others are wrong

  • B — FSx for Windows File Server targets Windows SMB workloads and does not provide a parallel HPC file system.
  • C — Accessing S3 objects directly over HTTPS gives high aggregate throughput but object semantics and higher per-request latency, which HPC simulation software expecting POSIX file access cannot use directly.
  • D — Amazon EFS is a general-purpose NFS file system. It is elastic and convenient but is not designed for the extreme parallel throughput HPC workloads require.

Last verified: 2026-09-02

Question 80 clf-core-services-overview-080

Intermediate · Choose one

An on-premises application must continue writing to a local file share for low-latency access, while the data is durably stored in Amazon S3 so cloud analytics tools can use it. Which AWS service provides this hybrid capability?

  1. a Amazon EFS mounted over the internet
  2. b AWS Storage Gateway
  3. c AWS DataSync
  4. d Amazon S3 accessed directly by the on-premises application over the internet
Show answer & explanation

Answer: B

Why B is correct

AWS Storage Gateway is a hybrid cloud storage service. The file gateway presents an SMB or NFS share on premises, caches frequently accessed data locally for low-latency reads, and stores the data durably as objects in Amazon S3, where other AWS services can consume it.

Why the others are wrong

  • A — Mounting EFS over the internet is not the intended access path, and it would provide no local cache, so every read would incur wide-area latency.
  • C — AWS DataSync is an online data transfer service that copies data between on-premises storage and AWS on a scheduled or one-time basis. It does not present an ongoing local cached file share.
  • D — Calling Amazon S3 directly would require rewriting the application to use the S3 API, and every read would cross the internet with no local cache, which fails the low-latency requirement.

Last verified: 2026-09-02

Question 81 clf-core-services-overview-081

Hard · Select 2 answers

Which TWO statements correctly describe the difference between an Amazon EC2 instance store and an Amazon EBS volume? (Choose TWO.)

  1. a Instance store volumes can be replicated across Availability Zones automatically
  2. b Instance store data is lost when the instance is stopped, hibernated, or terminated
  3. c EBS volumes are ephemeral and are automatically deleted when the instance stops
  4. d An EBS volume persists independently of the instance lifecycle and can be backed up with snapshots stored in Amazon S3
  5. e Instance store volumes can be detached from one instance and attached to another
Show answer & explanation

Answer: B and D

Why B and D are correct

An instance store provides temporary block-level storage physically attached to the host computer. Its data survives a reboot but is lost when the instance stops, hibernates, or terminates, or if the underlying disk fails. An Amazon EBS volume is network-attached and has its own lifecycle, so it persists when the instance stops and can be backed up using point-in-time snapshots that are stored in Amazon S3.

Why the others are wrong

  • A — Instance store data is not replicated by AWS at all. Any redundancy must be implemented by the application.
  • C — This reverses the two. EBS volumes are persistent; instance store volumes are ephemeral.
  • E — Instance store volumes are tied to the physical host and cannot be detached and reattached. That capability belongs to EBS volumes.

Last verified: 2026-09-02

Question 82 clf-core-services-overview-082

Hard · Choose one

A hospital stores medical images that must be retained for at least a year. Each image is accessed roughly once per quarter, but when it is accessed a clinician needs it in milliseconds. Which Amazon S3 storage class is the most cost-effective fit?

  1. a S3 Standard
  2. b S3 Glacier Instant Retrieval
  3. c S3 Glacier Deep Archive
  4. d S3 Glacier Flexible Retrieval
Show answer & explanation

Answer: B

Why B is correct

S3 Glacier Instant Retrieval is designed for long-lived archive data that is accessed about once per quarter but needs millisecond retrieval. It offers lower storage cost than S3 Standard-IA while still providing immediate access, with a 90-day minimum storage duration that a one-year retention easily satisfies.

Why the others are wrong

  • A — S3 Standard provides millisecond access but is the most expensive per gigabyte and is designed for frequently accessed data, so it wastes money on quarterly access.
  • C — S3 Glacier Deep Archive has retrieval times measured in hours, so a clinician could not open the image on demand.
  • D — S3 Glacier Flexible Retrieval requires a restore request and delivers data in minutes to hours, which does not meet a millisecond access requirement.

Last verified: 2026-09-02

Question 83 clf-core-services-overview-083

Hard · Choose one

An enterprise wants to define one set of backup policies and schedules and apply them centrally across Amazon EBS volumes, Amazon RDS databases, Amazon DynamoDB tables, and Amazon EFS file systems, with compliance reporting. Which AWS service should it use?

  1. a AWS Backup
  2. b AWS Elastic Disaster Recovery
  3. c Amazon Data Lifecycle Manager
  4. d Amazon S3 Versioning
Show answer & explanation

Answer: A

Why A is correct

AWS Backup is a fully managed, centralized backup service. Backup plans define schedules, retention, and lifecycle rules, and they are applied across supported AWS services including EBS, RDS, Aurora, DynamoDB, EFS, FSx, and Storage Gateway. It also provides audit and compliance reporting through AWS Backup Audit Manager.

Why the others are wrong

  • B — AWS Elastic Disaster Recovery continuously replicates servers for rapid recovery after a disaster. It is a DR replication tool rather than a policy-based backup catalog.
  • C — Amazon Data Lifecycle Manager automates the creation and retention of EBS snapshots and EBS-backed AMIs only. It does not cover RDS, DynamoDB, or EFS.
  • D — S3 Versioning protects objects within a single S3 bucket. It applies to no other service.

Last verified: 2026-09-02

Question 84 clf-core-services-overview-084

Hard · Choose one

Which statement about Amazon EBS volumes is TRUE?

  1. a An EBS volume exists in a single Availability Zone, and its snapshots are stored in Amazon S3 and can be copied to other Regions
  2. b An EBS volume automatically spans all Availability Zones in a Region for high availability
  3. c An EBS volume can be attached to an EC2 instance in any Availability Zone in the Region
  4. d EBS snapshots are stored on the EC2 instance's local disk and are lost if the instance terminates
Show answer & explanation

Answer: A

Why A is correct

An EBS volume is created in a specific Availability Zone and is automatically replicated within that zone to protect against component failure. Snapshots are incremental point-in-time backups stored durably in Amazon S3, and a snapshot can be copied to another Region, which is the standard way to move an EBS volume across Regions or Availability Zones.

Why the others are wrong

  • B — EBS volumes do not span Availability Zones. Cross-zone resilience must be built at the application layer or by restoring a snapshot into another zone.
  • C — A volume can only be attached to an instance in the same Availability Zone. To use it elsewhere you take a snapshot and create a new volume in the target zone.
  • D — Snapshots are stored in Amazon S3, managed by AWS, and are entirely independent of the instance's lifecycle.

Last verified: 2026-09-02

Question 85 clf-core-services-overview-085

Easy · Choose one

Which AWS service uses machine learning to identify objects, people, text, scenes, and activities in images and videos without requiring the customer to build a model?

  1. a Amazon Comprehend
  2. b Amazon Polly
  3. c Amazon Textract
  4. d Amazon Rekognition
Show answer & explanation

Answer: D

Why D is correct

Amazon Rekognition is a pre-trained computer vision service. It analyzes images and videos through a simple API to detect objects, scenes, activities, text in images, and faces, and to perform facial comparison and content moderation, with no machine learning expertise required.

Why the others are wrong

  • A — Amazon Comprehend is a natural language processing service that analyzes text for sentiment, entities, key phrases, and language. It does not process images.
  • B — Amazon Polly converts text into lifelike speech. It generates audio rather than analyzing visual content.
  • C — Amazon Textract extracts printed text, handwriting, forms, and tables from scanned documents. It is document-focused rather than general scene and object recognition.

Last verified: 2026-09-02

Question 86 clf-core-services-overview-086

Easy · Choose one

An e-learning company wants to turn its written course material into natural-sounding spoken audio in multiple languages and voices. Which AWS service should it use?

  1. a Amazon Polly
  2. b Amazon Translate
  3. c Amazon Transcribe
  4. d Amazon Lex
Show answer & explanation

Answer: A

Why A is correct

Amazon Polly is a text-to-speech service. It converts written text into lifelike speech using deep learning, offers many languages and voices including neural voices, and returns standard audio formats that can be played or stored.

Why the others are wrong

  • B — Amazon Translate performs machine translation of text between languages. It produces text, not audio, although it is often paired with Polly.
  • C — Amazon Transcribe performs the reverse operation, converting speech in audio files or streams into written text.
  • D — Amazon Lex builds conversational interfaces such as chatbots using automatic speech recognition and natural language understanding. It is not a bulk text-to-speech service.

Last verified: 2026-09-02

Question 87 clf-core-services-overview-087

Easy · Choose one

Which AWS service lets an analyst run standard SQL queries directly against data stored in Amazon S3, with no infrastructure to provision and charges based on the data scanned by each query?

  1. a AWS Glue
  2. b Amazon EMR
  3. c Amazon Athena
  4. d Amazon Redshift
Show answer & explanation

Answer: C

Why C is correct

Amazon Athena is a serverless, interactive query service. You point it at data in Amazon S3, define a table schema, and run standard SQL. There are no clusters or servers to manage, and you pay for the amount of data each query scans, which makes it well suited to ad hoc analysis.

Why the others are wrong

  • A — AWS Glue is an ETL and data cataloging service. Its Data Catalog supplies table definitions that Athena can use, but Glue itself is not the interactive SQL query engine.
  • B — Amazon EMR runs managed big data frameworks such as Apache Spark and Hadoop on clusters that the customer sizes and pays for while they are running.
  • D — Amazon Redshift is a data warehouse. Data is normally loaded into the warehouse, and the customer provisions a cluster or uses Redshift Serverless capacity.

Last verified: 2026-09-02

Question 88 clf-core-services-overview-088

Intermediate · Choose one

An insurance company receives thousands of scanned claim forms as PDFs each day and needs to automatically extract the printed text along with the form fields and table contents. Which AWS service is designed for this?

  1. a Amazon Rekognition
  2. b Amazon Transcribe
  3. c Amazon Textract
  4. d Amazon Comprehend
Show answer & explanation

Answer: C

Why C is correct

Amazon Textract goes beyond simple optical character recognition. It extracts printed text and handwriting and, importantly, preserves the structure of forms as key-value pairs and of tables as rows and columns, which is exactly what processing scanned claim forms requires.

Why the others are wrong

  • A — Amazon Rekognition can detect text in images, but it returns detected text elements without understanding form field relationships or table structure.
  • B — Amazon Transcribe converts speech in audio and video into text. It processes audio, not scanned document images.
  • D — Amazon Comprehend analyzes text that has already been extracted. It is commonly used after Textract rather than instead of it.

Last verified: 2026-09-02

Question 89 clf-core-services-overview-089

Intermediate · Choose one

A retailer wants to analyze thousands of free-text customer reviews to determine whether each is positive, negative, neutral, or mixed, and to identify the products and brands mentioned. Which AWS service should be used?

  1. a Amazon Translate
  2. b Amazon Comprehend
  3. c Amazon Quick Sight
  4. d Amazon Polly
Show answer & explanation

Answer: B

Why B is correct

Amazon Comprehend is a natural language processing service that uses machine learning to find insights in text. It performs sentiment analysis, entity recognition, key phrase extraction, language detection, and topic modeling without requiring the customer to train a model.

Why the others are wrong

  • A — Amazon Translate converts text from one language to another. It does not determine sentiment or extract entities.
  • C — Amazon Quick Sight (formerly Amazon QuickSight) is a business intelligence service for building dashboards and visualizations. It presents results but does not perform the natural language analysis.
  • D — Amazon Polly converts written text into lifelike speech. It produces audio and performs no sentiment or entity analysis.

Last verified: 2026-09-02

Question 90 clf-core-services-overview-090

Intermediate · Choose one

A data team needs a serverless service that can discover and catalog data sources, infer their schemas, and run extract, transform, and load jobs to prepare data for analytics. Which AWS service provides this?

  1. a Amazon Athena
  2. b Amazon EMR
  3. c Amazon Redshift
  4. d AWS Glue
Show answer & explanation

Answer: D

Why D is correct

AWS Glue is a serverless data integration service. Crawlers scan data stores, infer schemas, and populate the AWS Glue Data Catalog, which acts as a central metadata repository. Glue then runs ETL jobs, with no clusters for the customer to provision or manage.

Why the others are wrong

  • A — Amazon Athena queries data in place using SQL. It consumes the Glue Data Catalog rather than creating it, and it does not run transformation pipelines.
  • B — Amazon EMR runs big data frameworks such as Apache Spark and Hadoop on clusters the customer sizes and manages. It can perform transformations but is not serverless and does not provide the central Data Catalog.
  • C — Amazon Redshift is a data warehouse. It stores and analyzes data that has been loaded into it, rather than crawling external sources to infer schemas and run transformation pipelines.

Last verified: 2026-09-02