“At its most basic, filetyping is how an OS associates a file
with the appropriate application, which allows the user to easily
work with the file and which gives other applications information
about the file. Without this basic functionality, the user has to
personally associate all files with their appropriate applications.
On a more sophisticated level, however, filetypes essentially
dictate how the user interacts with data.”
“Filetyping on Linux and Windows allows only the filetype to
be stored with the file, and all other information, including
preferred application, must be stored as an OS preference,
whereas MacOS and BeOS provide extra room with the file for storing
whatever information is desired.”
“BeOS, has added two important pieces that no other OS
appears to use. First, BeOS uses the MIME typing system. This
defines super- and subtypes of files, as well as provides a
mechanism for industry-wide definitions. … Further, BeOS uses
its attribute capabilities to actually store information about the
contents of the file — for instance storing the title,
artist, and album of an MP3.”