What is a presigned URL in AWS - sharing a private file safely
A presigned URL is a normal-looking web link that lets someone download or upload one specific file in a private Amazon S3 bucket, for a lim...
Category: AWS
What is eventual consistency - the S3 promise, honestly
No — Amazon S3 has not been "eventually consistent" since December 1, 2020. Every PUT, GET, DELETE, and LIST against an S3 object ...
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What is object storage vs block vs file in AWS - S3/EBS/EFS in plain terms
Object, block, and file storage are three different ways of handing your data to a computer, and on AWS they map to three specific services:...
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What is snapshot in AWS - and how incremental saves you money
A snapshot is a point-in-time copy of your data — but on Amazon EBS, only the very first one is a full copy. Every snapshot after that is in...
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What is an AMI - the frozen server explained
An AMI (Amazon Machine Image) is not a server. It is a frozen, reusable template of one — the operating system, the installed software, and ...
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What is the AWS free tier really - three kinds, one page
The AWS Free Tier is not one thing. As of today it's two permanent things — Always Free services with a monthly allowance that never ex...
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What is an IAM policy - the JSON that grants everything
An IAM policy is a JSON document that tells AWS what a person or a system is allowed to do — and to what. That's it. No agent, no daemon...
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What is an EBS volume vs an instance store
An EBS volume is a separate, durable disk that lives on AWS's network and keeps your data even if the instance attached to it is stoppe...
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S3 NoSuchBucket But the Bucket Exists: Every Fix
"NoSuchBucket" on an S3 operation almost always means one thing: your request went to the wrong region. But here is the part almos...
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S3 AccessDenied on GetObject: Every Real Cause in Order
"AccessDenied" on an S3 GetObject call means one specific thing: somewhere in the policy chain, a deny beat your allow — and the f...
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What Is Amazon EKS? Kubernetes, Rented
Amazon EKS (Elastic Kubernetes Service) is AWS's managed Kubernetes service — AWS runs the Kubernetes control plane (the API server, th...
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What Is Amazon ECR? The Shelf Your Images Live On
Amazon ECR (Elastic Container Registry) is a fully managed container image registry that stores, manages, and serves Docker and OCI images f...
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What Is AWS MFA and Why AWS Nags You - Set It Up in 3 Minutes
MFA stands for multi-factor authentication, and on AWS it means proving who you are with two things instead of one: your password, plus a ro...
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What is the root user vs an IAM user - and why you stop using root
The AWS root user is the single all-powerful login created the moment you sign up for an AWS account, and an IAM user is a separate, limited...
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What is an instance profile - how EC2 gets permissions
An instance profile is the small container AWS uses to physically hand an IAM role to an EC2 instance — without it, the role you created has...
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What is a security group - a firewall you will actually understand
A security group is AWS's version of a firewall for your cloud resources — but it's a firewall with one rule you won't find on a...
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What is a service-linked role - the roles AWS makes for you
A service-linked role is an IAM role that AWS itself creates, names, and owns inside your account so a specific service can call other AWS s...
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AWS Fargate Explained: Run Containers Without Managing Servers (Beginner's Guide)
AWS Fargate is a serverless compute engine that runs your containers without you ever seeing or managing a server. Unlike ECS (which orches...
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What is Amazon ECS? Container Orchestration Without the Kubernetes Complexity
Amazon Elastic Container Service (ECS) is a fully managed container orchestration service that runs Docker containers on AWS without requiri...
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What is a VPC subnet - public vs private in one picture
A subnet in an AWS VPC is public if its route table sends internet-bound traffic (0.0.0.0/0) to an internet gateway, and private if it doesn...
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