FreeDOS will run on actual Hardware, Virtual Machines, and even Modern Hardware, though each one has it's own caveats.

On actual Vintage Hardware, you will need the Legacy Boot CD or Floppy Distribution to install depending on the vintage of your computer. Most computers from the 386 on back will require the Floppy Distribution, while a 386 or better with a Dynamic Drive Overlay on a large Hard Disk - such as OnTrack 9 - can leverage this feature to boot off of the LEGACY CD media to install (the latter is how I do this on my own computers).

On Modern Hardware - bare metal - you can install FreeDOS using a USB Distribution including a LiveUSB that allows you to use it without installing it, and a USB Distribution that will install to your modern PC's hard disk. For FreeDOS, Modern is defined as anything post Pentium II pretty much. It will run on these systems, but the caveat is you might need some more modern specialized utilities to get the best experience, such as the SoundBlaster Driver Utilites found on the VOGONS Forum to ustilize a modern sound card like a vintage SoundBlaster card.

And lastly you can use VirtualBox, or any other Virtual Machine Software, and run FreeDOS in that sort of environment, allowing you to concurrently use it with your modern Linux/MacOS/Windows Operating system without rebooting. This is a very popular option these days to save space, time, and money.

That said, using legacy computers, you might run into problems with some more esoteric systems such as the Tandy 1000, Olivetti/AT&T PC 6300, possibly some WYSE/Amdek systems, or anything that's quite a bit "off" from the standard. For these systems, we suggest using the version of DOS they came with, or MS-DOS 6.22. Mostly this covers older (286 and older) syystems moreso than stuff from the 386SX/DX on up.