Emulators, such as Yuzu (which recently shut down due to legal pressure) or Ryujinx, are software programs that mimic Switch hardware to allow these ROMs to run on PCs, Android devices, or even jailbroken Switches.
A study of gaming piracy sites found that over 60% of "download" buttons led to adware installers rather than actual game files. nintendo switch roms free
Here is a guide to understanding the current state of Switch ROMs, the risks involved, and how to stay on the right side of the law. The Truth About "Free" ROM Sites Emulators, such as Yuzu (which recently shut down