The shared responsibility model explains how security duties are divided between a cloud provider and the customer using the service.
The shared responsibility model describes how security duties are divided between a cloud provider and the customer. In plain language, the provider secures some parts of the cloud service, while the customer still has important responsibilities for how that service is configured, used, and governed.
This model matters because cloud security confusion often comes from wrong assumptions about ownership. A team may believe that because a workload runs in the cloud, the provider handles every security task. In reality, many access, configuration, data, and monitoring decisions remain the customer’s job.
It also matters because the exact responsibility split changes by service type. A SaaS application, a managed database, and an infrastructure-level virtual machine do not create the same customer obligations.
The shared responsibility model appears in cloud architecture, compliance review, onboarding of managed services, and security training. Teams use it to decide who patches what, who configures access, who protects data, and who monitors the environment.
Security teams rely on this model when they investigate misconfigurations, evaluate provider features, and design controls such as Cloud Security Posture Management, Secrets Management, and Least Privilege for cloud access.
A company uses a managed cloud storage service. The provider operates the underlying infrastructure, but the company still decides which users can access the data, whether public access is allowed, how encryption settings are configured, and how suspicious activity is monitored.
The shared responsibility model does not mean the customer and provider handle every control equally. Responsibilities are divided, not duplicated symmetrically.
It is also not a cloud-provider marketing slogan. It is a practical operating model that explains why customers remain accountable for many security outcomes even when they outsource infrastructure layers.