Cloud shared responsibility model explained, who secures what
The shared responsibility model is the contract that decides which security controls belong to the cloud provider and which belong to you. The line moves depending on the service tier: IaaS gives you the most control and the most responsibility; SaaS the least of both. Mistaking which side a control falls on is one of the most common, and most expensive, cloud security mistakes.
Why What is the cloud shared responsibility model? matters
Compliance audits, breach investigations, and incident-response retros consistently find that the misunderstanding of who owns what control caused the gap. Treating S3 server-side encryption as 'AWS handles encryption' misses that you still chose the key, the rotation policy, and who could decrypt.