What Is Dynamic Update? on Windows 10

Dynamic Update is a feature of the Windows 10 l Setup program that allows you to download updated files that are used during the installation of Windows 10. Setup uses Dynamic Update to query the Windows Update site prior to installing Windows 10 to obtain the following files:

Critical Updates Setup downloads any available replacements for files on the Windows 10  installation CD.

Device Drivers Setup also downloads any available hardware driver replacement files for drivers found on the Windows 10  installation CD.

To use Dynamic Update during Setup, your computer must have a working Internet connection. For this reason, Dynamic Update is available only when you start a clean installation or upgrade from within an existing installation of Windows. When Setup asks whether it should look for updates, click Yes to have Setup search for and install available updates.
 
Dynamic Upcblate is also enabled by default during unattended installations
Important Setup does not use Dynamic Update to download any updates that are not already included on the installation CD, so even if you use Dynamic Update, you should still use the Windows Update site or the Windows Automatic Updates feature to obtain critical updates following installation.