DevOps
Cloud Infrastructure
Amazon Web Services
Amazon S3: Basics

Amazon S3: Basics

Amazon Simple Storage Service (S3) is an object storage service that offers industry-leading scalability, data availability, security, and performance. Transitioning from traditional block storage to object storage allows you to store and protect any amount of data for a range of use cases.


📦 Core Concepts: Buckets & Objects

Unlike a traditional file system with folders and files, S3 uses a flat structure of Buckets and Objects.

  • Buckets: Fundamental containers for data. Bucket names are globally unique across all AWS accounts.
  • Objects: The fundamental entities stored in S3. An object consists of data, a key (its unique identifier), and metadata.
  • Keys: The full path to the object (e.g., uploads/images/profile.jpg).

⚡ S3 Storage Classes

Optimize your costs by choosing the right storage class based on how often you need to access your data.

Storage ClassUse CaseDurabilityAvailability
S3 StandardFrequently accessed data (Active data).99.999999999%99.99%
S3 Standard-IAInfrequently accessed but needs rapid access.99.999999999%99.9%
S3 One Zone-IANon-critical, infrequent data (Cheaper).99.999999999%99.5%
S3 GlacierLong-term archive (Retrieval in mins/hours).99.999999999%99.9%
S3 Glacier Deep ArchiveMulti-year archiving (Retrieval in 12-48 hrs).99.999999999%99.9%
Intelligent-TieringAutomatically moves data between tiers.99.999999999%99.9%

đź’Ž Key Features of S3

1. Unmatched Durability

S3 is designed for "11 Nines" (99.999999999%) durability, meaning your data is redundantly stored across multiple devices in a minimum of three Availability Zones (AZs) within an AWS Region.

2. Versioning

Enabling Versioning allows you to keep multiple variants of an object in the same bucket. This provides a safety net against accidental deletions or overwrites.

3. Static Website Hosting

You can configure an S3 bucket to host a static website (HTML, CSS, JS, Images). This is a highly scalable and cost-effective alternative to running a web server.

4. Security & Access Control

  • Block Public Access: A cluster-level setting to ensure no data is accidentally exposed.
  • Bucket Policies: JSON-based access control rules.
  • Encryption: Automatically encrypts data at rest via SSE-S3 or SSE-KMS.

[!NOTE] S3 is Region-Specific! While bucket names are global, the bucket itself lives in a specific AWS Region. Choose the region closest to your users for the lowest latency.