Windows 10 virtual desktops allow you to create different desktops that can be used to organize open applications and data. The problem is that each desktop will be given a similar generic name such as Desktop1, Desktop2, etc. This can make it confusing and hard to find the particular desktop you are looking for. With the release of Windows 10 Insider build 18975, Microsoft now let’s you rename any virtual desktop to a custom name. To rename one of them, simply click on its name and the field will become editable.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-to-let-you-rename-virtual-desktops-heres-how/