# Cloud Security

The practices, policies, and technologies used to protect data and systems hosted in cloud services.

**Cloud security[↗](/cloud-security)** is the set of measures, policies, and technologies used to protect the data and systems (servers, storage, applications, databases) held in cloud services. Because resources run on a provider's infrastructure rather than an organization's own premises, security has some distinct requirements.

At the center of cloud security is the "shared responsibility model": the provider is responsible for the security of the physical infrastructure and core services, while access settings, identity management, data classification, and correct configuration are largely the customer's responsibility. Misunderstanding this boundary is one of the most common sources of security gaps.

Indeed, most cloud breaches stem not from a flaw at the provider but from misconfiguration: storage accidentally left publicly accessible, overly broad access permissions, or default settings that were never turned off. That's why least privilege, multi-factor authentication[↗](/authentication), data encryption[↗](/data-encryption), and regular configuration audits are the cornerstones of cloud security.