How to work with basic header files

To work with basic header files.

Header File	Purpose Of Use
conio.h	Screen – handing function
ctype.h	Character – handing function (ANSI C)
float.h	Define Implementation dependant floating point
iomanip.h	Define I/O manipulator
iostream.h	Defines I/O stream class (C++)
math.h	Various definitions used by math library.
stdio.h	Declaration for standard I/O stream
string.h	String handling
time.h	System time function