What are the five FSMO roles in Active Directory forest with one parent and two child domains?

There are five roles:

They are further classified in two

• Schema Master - As name suggests, the changes that are made while creation of any object in AD or changes in attributes will be made by single domain controller and then it will be replicated to another domain controllers that are present in your environment. There is no corruption of AD schema if all the domain controllers try to make changes. This is one of the very important roles in FSMO roles infrastructure.
• Domain Naming Master - This role is not used very often, only when you add/remove any domain controllers. This role ensures that there is a unique name of domain controllers in environment.

• Infrastructure Master - This role checks domain for changes to any objects. If any changes are found then it will replicate to another domain controller.
• RID Master - This role is responsible for making sure each security principle has a different identifier.
• PDC emulator - This role is responsible for Account policies such as client passWord changes and time synchronization in the domain