Answer - The main advantage of having a system that supports multiple file structures is that the support for it is provided by the system itself no other individual application is required to provide the multiple structure support. Since the support is provided by the system itself the implementation is much more efficient as compared to application level. A demerit of such kind of implementation is that it can increase the overall size of the system. Also, since the support is provided by the system, for an application that requires a different file type may not be executable on such a system. A good alternative for this is that the OS does not define any support for file structures instead all files are considered to be a series of bytes. By doing so the support for file systems is simplified as the OS does not have to specify the different structures for the file systems. It allows the applications to define the file structures. This kind of implementation can be found in UNIX.