filebuf − Its purpose is to set the file buffers to read and write. Contains open() and close() as member function.
fstreambase − Provides operations common the file streams. Services as a base for fstream, ifstream and ofstream class.
ifstream − Provide input operations. Inherits the functions get (), getline (), read (), seekg() and tellg() functions from istream.
ofstream − Provides output operations. Inherits put (), seekp(), tellp () and write () functions from ostream.
fstream − Provides support for simultaneous input and output operations. Inherits all the functions from istream and stream classes through iostream.