AWS service for centrally managing multiple AWS accounts. Like having a corporate headquarters that manages all branch offices with consistent policies.
Large enterprises use AWS Organizations to apply security policies and manage billing across hundreds of AWS accounts.
All provide hierarchical governance across multiple accounts/projects/tenancies: grouping, policy enforcement, and centralized administration. AWS Organizations focuses on multi-account management with OUs, SCPs, and consolidated billing; Azure uses Management Groups with Azure Policy; GCP uses Organization/Folder/Project with IAM and Org Policies; OCI uses tenancy/compartment structure with IAM policies and governance.