Simple definition
The Infrastructure Master FSMO role updates references to objects from other domains in Active Directory.
Purpose and use
The Infrastructure Master is an Active Directory FSMO, Flexible Single Master Operation, role involved in maintaining selected cross-domain object references.
How does it work?
Its holder compares and updates reference information according to directory configuration; useful activity depends in part on enabled features and global-catalog placement.
Example and verification
During role review, identify the holder and forest structure before applying placement advice from another context.
Points to watch
The role does not control all replication or act as a universal server master. Guidance can differ with AD Recycle Bin and global-catalog deployment.
In short
Understand the role within directory architecture, including its specific scope and dependencies.