Which AWS service or feature allows users to create new AWS accounts, group multiple accounts...

AWS Organizations is the AWS service or feature that allows users to create new AWS accounts, group multiple accounts to organize workflows, and apply policies to groups of accounts. AWS Organizations enables users to centrally manage and govern their AWS environment across multiple accounts. Users can create organizational units (OUs) to group accounts based on their business needs, such as by function, project, or region. Users can also apply service control policies (SCPs) toOUs or individual accounts to define the permissions and restrictions for the AWS services and resources that they can access. AWS Organizations also offers features such as consolidated billing, account creation automation, and trusted access12. References:

AWS Organizations

What is AWS Organizations?