Someone connects a bunch of Mac’s to the internet and then you can sign in on one of those Macs via a Remote Desktop Connection (RDP). It only runs on macOS! What if you don't have a Mac PC? This post from MiniTool Partition Wizard tells you how to use Xcode on Windows. Xcode is an integrated development environment provided by Apple to developers for developing applications for macOS, iOS, iPadOS, WatchOS and tvOS.
