DOSBox is a DOS-emulator that uses the SDL-library which makes DOSBox very easy to port to different platforms. DOSBox has already been ported to many different platforms, such as Windows, BeOS, Linux ...
FreeDOS is an operating system that can run MS-DOS programs natively and will appeal more to enthusiasts. DOSBox is an emulator that simplifies running MS-DOS programs but comes with some limitations.
For many people, the golden age of PC gaming was the DOS era. Or maybe that is just my nostalgia kicking in. Either way, emulation is the key to reliving those days, playing old games that are neither ...
The major benefit I see in DOSBox Pure over DOSBox Classic is a sort of built-in containerization for games. DOSBox Pure creates a separate environment for each game automatically when it's "opened" ...