• Although there is a distinction between the First Domain Controller (DC) and further Domain Controllers (ADCs), these Domain Controllers are identical. By default, the first Domain Controller is a Global Catalog (GC) that manages all five FSMO responsibilities. ADCs can be made Global Catalogs, and FSMO roles can be transferred between Domain Controllers. There is no difference in terms of functionality.
• People frequently distinguish between the initial Domain Controller and additional Domain Controllers (ADCs), yet there may be no distinction between the two. By default, the first Domain Controller is a Global Catalog (GC) that manages all five FSMO responsibilities. ADCs can be made Global Catalogs, and FSMO roles can be transferred between Domain Controllers.

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