Original sentence: A file on DOS or Unix is simply a sequence of bytes, requiring an application to know which bytes represented code and which were graphic or other data.A text file could contain its text in the data fork and styling information in its resources, so that an application which didn't recognize the styling information could still read the raw text.An file might consist only of resources with an empty data fork, or only a data fork with no resource fork.Both file systems are otherwise the same.By contrast, MFS and HFS gave files two different "forks".In addition to the data fork, which contained the usual sequence of bytes, there was a resource fork which contained structured data such as menu definitions, graphics, sounds, or code segments.Mac OS originally used the Macintosh File System, a flat file system with only illusory folders.On the other hand, forks provided quite a challenge to interoperation with other operating systems; copying a file from a Mac to a non-Mac system would strip it of its resource fork.This was promptly replaced by the Hierarchical File System, which had a real directory tree
Edited sentence: A text file might contain its text in the data fork and styling information in its resources, so that an application which didn't recognize the styling information could still read the raw text.An application file might consist only of resources with no data fork.By the late 1990s, it was clear the useful life of this 1980s-era technology was coming to an end, with other more stable multitasking operating systems being developed.Despite the many assets of this arrangement, it became quite a challenge to interoperate with other operating systems which did not recognize such a system; for example, copying a file from a Mac to DOS or Unix would strip it of its resource fork.In addition to the data fork, which contained a sequence of bytes, there was a resource fork which contained structured data such as menu definitions, graphics, sounds, or code segments.Mac OS also introduced the Hierarchical File System, an innovative new type of filesystem.Whereas a file on DOS or Unix would simply be a sequence of bytes, requiring an application to know which bytes represented code and which were graphic or other data, Mac files had two different "forks"