What is equivalent to a Linux user group in a Windows Server environment?

In a Windows Server environment, the concept equivalent to a Linux user group is a Security Group. A Security Group is used to manage permissions for a set of users collectively, allowing administrators to assign rights or access to resources in a more efficient manner. This group approach mirrors how Linux manages users through groups; it allows multiple users to share the same set of permissions without assigning access rights individually.

Active Directory is more of an overarching directory service that can include various objects, including users and groups, but it is not equivalent to a user group specifically. User Profiles pertain to the individual settings and data for a specific user, not a grouping of users. A Workgroup refers to a network model in which computers are grouped together in a decentralized manner, but it doesn't represent a method of managing user permissions like Security Groups do. Thus, the proper analogy in Windows Server to a Linux user group is indeed the Security Group.