In the modern enterprise, deploying Microsoft 365 (formerly Office 365) is no longer a matter of clicking "Next" on a setup wizard. For IT administrators managing hundreds or thousands of devices, consistency, efficiency, and control are paramount. At the heart of this automated deployment lies a small but powerful text file: the Office 365 configuration XML . Far from being just another configuration file, it serves as the declarative blueprint that dictates exactly how the Office suite is installed, updated, and maintained across an organization. What is the Office Deployment Tool (ODT) and its XML? The Office Deployment Tool (ODT) is a command-line executable ( setup.exe ) provided by Microsoft. However, the ODT itself does nothing without instructions. Those instructions are written in an XML (Extensible Markup Language) file. When an administrator runs setup.exe /configure configuration.xml , the tool reads every tag and attribute within that XML to execute the installation precisely as defined.