There's a good explanation on RAM disks here: kingston[.]com/en/blog/pc-performance/what-is-ram-disk
RAM disks were more of a thing when we were limited by the relatively slow speed of conventional hard disks, but SSDs & then NVMe SSDs have gotten EXTREMELY fast at the high end, so RAM disk use isn't all that common nowadays. While a RAM disk is still faster than an SSD, you have to actually use that higher speed to make a real difference, and that's not easy with the fastest NVMe drives, let alone with a RAM disk. That said, using a RAM disk is cheaper than buying a fast NVME drive [or any NVMe drive for that matter], and the fact that all data stored on a RAM disk is gone the moment they lose power may be an advantage in some situations -- copy the VHD with a VM on it to a RAM disk and run it from there, and anything you do in or with that VM disappears without any trace whatsoever with a restart or power off.
You can find free and paid RAM disk software online similar to Gilisoft's. I think all RAM disk software will add a driver, and Gilisoft Ramdisk also adds a Windows service. Its installation isn't bad but it's a little bit more complicated... Beside the program's folder and a folder in Users\ [UserName]\ AppData\ Roaming\, you get an empty folder in Documents, 2 files in C:\ Windows\, magicskin.dll & RDAPI_2K.dll, 5 files in Windows\ Inf\, GsRamDsk.cat, GsRamDsk.inf, GsRamDsk.sys, + an oemX.inf & oemX.pnf, where X = some number [it was 10 in my VM]. You get a folder in C:\Windows\ System32\ DriverStore\ FileRepository\ gsramdsk.inf_amd64_4a98981febcfe00a\, and a driver file C:\Windows\ System32\ drivers\ GsRamDsk.sys. The registry doesn't get a Gilisoft key for the app, but it has 2 for the activation key, adds an uninstall key, plus registry entries for the driver and service.