Input Output
Most languages have "statements" to perform I/O . Though in C and C++ we use "functions" to perform I/O. C++ also has its own I/O mechanism - the cin and cout objects, declared in the header file iostream.h.
On including iostream.h , the program gets the following 4 objects automatically:
Cin- This object corresponds to the standard input Stream, which by default is the keyboard.
Cout- This object corresponds to the standard output stream ,which by default is the screen.
cerr & clog- This object corresponds to the standard error stream, which by default is the screen.