C C + + each header file's function says

Functional description of each header file in C + +

Traditional C + +
#include <assert.h>//Set insertion point
#include <ctype.h>//character processing
#include <errno.h>//define error codes
#include <float.h>//floating-point processing
#include <fstream.h>//File input/output
#include <iomanip.h>/Parametric input/output
#include <iostream.h>//data stream input/output
#include <limits.h>//define a variety of data type MAX-values constants
#include <locale.h>//define localization functions
#include <math.h>//defining mathematical functions
#include <stdio.h>//define input/output functions
#include <stdlib.h>//define miscellaneous functions and memory allocation functions
#include <string.h>//String processing
#include <strstrea.h>//array-based input/output
#include <time.h>//define functions for TIME
#include <wchar.h>//wide character processing and input/output
#include <wctype.h>//Wide character categories

//////////////////////////////////////////////////////////////////////////

Standard C + + (no longer annotated with IBID.)
#include <algorithm>//stl General algorithm
#include <bitset>//stl bit set container
#include <cctype>
#include <cerrno>
#include <clocale>
#include <cmath>
#include <complex>//plural class
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>//stl Dual-ended queue container
#include <exception>//exception handling classes
#include <fstream>
#include <functional>//stl Defining an operation function (instead of an operator)
#include <limits>
#include <list>//stl Linear list container
#include <map>//stl mapping container
#include <iomanip>
#include <ios>//Basic input/output support
#include <iosfwd>//input/output system use of the predecessor declaration
#include <iostream>
#include <istream>//Basic input stream
#include <ostream>//Basic output stream
#include <queue>//stl Queue container
#include <set>//stl Collection container
#include <sstream>//string-based streaming
#include <stack>//stl Stack container
#include <stdexcept>//Standard Exception class
#include <streambuf>//Bottom input/output support
#include <string>//String class
#include <utility>//stl Generic template class
#include <vector>//stl dynamic array container
#include <cwchar>
#include <cwctype>

using namespace Std;

//////////////////////////////////////////////////////////////////////////

C99 Increase
#include <complex.h>//complex processing
#include <fenv.h>//floating-point environment
#include <inttypes.h>//integer format conversion
#include <stdbool.h>//Boolean environment
#include <stdint.h>//Integral environment
#include <tgmath.h>//general type Math macro

Reference:
http://blog.csdn.net/gencheng/article/details/7309651
http://blog.csdn.net/gencheng/article/details/7309629

C C + + each header file's function says