As detailed in a Microsoft Blog Post, dynamic refresh rate is new a feature coming to Windows 11 that will allow the operating system to dynamically change your screen's refresh rate to save power consumption.
This type of refresh rate manipulation is a bit different from the current variable refresh rate we have today in Windows 10. With dynamic refresh rate, the goal is to improve power consumption when using 2D applications on the desktop, like emails, web browsers, and word processors.
Let's say you're typing an email to somebody. The screen doesn't need to be refreshing at its maximum of 120Hz to keep up, as an example. When Windows 11 sees you aren't doing anything that requires a higher refresh rate, it will cut your monitor's refresh rate down to 60Hz automatically to save power. If you have an android smartphone with variable refresh rate, it's the same idea.
But the instant you start scrolling down a webpage or moving a window around, Windows will automatically boost the refresh rate back to 120Hz (or whatever your display supports), giving you a very fluid desktop experience.
This feature will be most beneficial for laptops, but Microsoft doesn't say if this feature will be laptop exclusive. So we could see this feature being unlocked for both notebook and desktop computers.
To support the new dynamic refresh rate feature, you will need an adaptive refresh rate monitor, whether that be FreeSync or G-Sync of any kind, and it needs to support at least 120Hz or greater. (We're not sure why 100Hz or 75Hz panels won't work at this time.)
Plus, your graphics card will need to support the new WDDM 3.0 standard. This is a new update exclusive to Windows 11 that adds a few features like better graphical support for Linux apps and the ability to assign different apps to different GPUs simultaneously. Right now, it's not clear which GPUs are getting WDDM 3.0 support.
Microsoft has also noted that Dynamic refresh rate will need to be an app-supported feature to work. So if you fire up an app that doesn't support the feature, dynamic refresh rate will disable itself. For now, the only app that supports DRR is Microsoft Office.