Here are the data structures with brief descriptions:

CPHYSFS_Allocator	PhysicsFS allocation function pointers
CPHYSFS_ArchiveInfo	Information on various PhysicsFS-supported archives
CPHYSFS_Archiver	Abstract interface to provide support for user-defined archives
CPHYSFS_File	A PhysicsFS file handle
CPHYSFS_Io	An abstract i/o interface
CPHYSFS_Stat	Meta data for a file or directory
CPHYSFS_Version	Information the version of PhysicsFS in use