Ref: https://learn.cantrill.io/courses/1820301/lectures/41301623 and https://www.udemy.com/course/aws-certified-cloud-practitioner-new/learn/lecture/20055904

DEMO: https://learn.cantrill.io/courses/1820301/lectures/41301625

• Summary
• Contents:

Amazon S3 - Key Concepts

• 🔧 AWS’s default storage service
  • Object Storage (NOT file storage, NOT block storage)
    • Stores objects (data) & buckets (containers of objects)
  • 👍 Perfect for hosting large data sets (movies, audio, photos, text, unstructured data…)
    • Economical
    • Access via UI/CLI/API and even HTTP(S)
  • 👍 Public service, unlimited data & multi-user
  • Many AWS products use S3 as their default data input and/or output
• ‼️ S3 is a global storage platform, but is regionally based/resilient!!
  • Data stored in regions
    • Data replicated across AZs of the region
  • ~~S3 bucket names must be globally unique~~ → ‼️ MARCH2026 UPDATE!!! → AWS relaxed requirement of S3 bucket names being globally unique. Account regional namespaces allow creating buckets within your own reserved namespace.

    • When creating S3 bucket, can choose global OR (newly recommended) account regional namespace (see screenshot)

      

    • Under the hood, bucket names all get appended suffix (which is unique to your account & region)

    • More info: https://aws.amazon.com/blogs/aws/introducing-account-regional-namespaces-for-amazon-s3-general-purpose-buckets/

• Since S3 is Object Store…:
  • It is NOT File Store → can't browse an S3 bucket like a File System
    • 💡 Amazon EFS or Amazon FSx provide file storage
  • It is NOT Block Store → can't mount an S3 bucket as K:\ or /images
    • 💡 Use Amazon EBS for mountable block storage

S3 Objects

• 💡 objects ≈ files (often conceptually interchangeable… but strictly speaking they're different)
• Components
  • Key → identifies the object in a bucket
    • e.g. apple.png
    • 💡 Same function as what a filename is to a file
  • Value → data/contents of the object
    • can range from 0B to 50TB → S3 is very scalable!
    • ‼️ 50TB is the maximum size of an S3 object, and it's a HARD LIMIT!! (memorize)
  • Other components: Version ID, metadata, access control list (ACL), subresources
• An object is placed inside a bucket, cannot exist without it

S3 Buckets

• 🔧 S3 Bucket = container of S3 objects
  • Created in a region → stable & controlled data sovereignty
    • Its data never leaves the region unless configured to do so
  • Can hold an unlimited number of objects → S3 is an infinitely scalable storage system
• Bucket name → identifies the bucket (across the whole AWS!)
  • e.g. fruitsdata
  • ‼️ Historically, bucket names had to be globally unique!! (across ALL regions & ALL AWS accounts!)
    • 💡 This is why the ARN of an S3 Bucket did not include the region it's stored in
      • e.g. arn:aws:s3:::koalacampagin13333337
    • ❗ But as mentioned above, this restriction is no longer there → Account regional namespaces allow creating buckets within your own reserved namespace → the bucket name gets an additional suffix (unique to region and account) → reflected in the ARN
  • Bucket naming restrictions:
    • 3-63 characters, all lower case, no underscores
    • Must start with lowercase or number
    • Can not be formatted like IP addresses (e.g. 1.2.3.4)