What it is
The shared responsibility model splits security between the cloud provider and you. AWS and Azure both publish a version of this diagram. The diagram is not decorative.
They secure the facilities, hardware, and the core services they run. You secure what you put in those services: identities, data, configurations, network rules, and applications.
The exact line shifts by service. A managed database still leaves you responsible for access and encryption choices. A virtual machine leaves you responsible for almost everything above the hypervisor. "It is in the cloud" does not move that line.
Why it matters in the meeting
Teams sometimes assume "the cloud is secure" means "we do not have to do anything." That is the gap auditors write up, usually with a polite frown and a finding ID.
When Bart says the provider secures the building, he is not saying your work is done. He is saying you still lock the doors to your office. Selena's open bucket is your door, not Amazon's.
Real world
Misconfigured storage buckets, open security groups, and missing encryption are customer-side failures. The provider did its part. The account did not.
Understanding the split is how you know which questions belong to engineering and which belong to the vendor. "Is AWS secure?" is the wrong question. "Did we turn on encryption and close public access?" is the right one.
Shared responsibility is not shared blame. The cloud company runs the building. You lock your floor. Confusing the two is how a public bucket becomes a company story.
What to ask
- For this workload, what is on our side of the line versus the provider's?
- Who owns encryption, identity, and network rules for production?
- If a bucket went public tonight, is that a vendor incident or ours?
- Have we read the shared responsibility page for the services we actually use, or only the marketing slide?
You just knew a little more Jack than you did five minutes ago.
All concepts