Amazon Resource Access Manager (RAM) helps you securely share your resources across Amazon Web Services accounts, within your organization or organizational units (OUs) in Amazon Web Services Organizations, and with IAM roles and IAM users for supported resource types. You can use Amazon RAM to share transit gateways, subnets, Amazon License Manager license configurations, Amazon Route 53 Resolver rules, and more resource types.

Many organizations use multiple accounts to create administrative or billing isolation, and to limit the impact of errors. With Amazon RAM, you don’t need to create duplicate resources in multiple Amazon Web Services accounts. This reduces the operational overhead of managing resources in every account that you own. Instead, in your multi-account environment, you can create a resource once, and use Amazon RAM to share that resource across accounts by creating a resource share. When you create a resource share, you select the resources to share, choose an Amazon RAM managed permission per resource type, and specify whom you want to have access to the resources. Amazon RAM is available to you at no additional charge.