Windows Server 2016

*Need some help understanding this* (and if you have a source please let me know so I can further research and learn)

You are the network administrator for your organization. You have a reference computer that runs Windows Server 2016. You need to create and deploy an image of the Windows Server 2016 computer. You create an answer file named answer.xml. You must make sure that the installation applies the answer file after you deploy the image.

Which command should you run before you capture the image; why should you run this command? What steps would you take to run this command?