The C++ and C library is a set of functions, constants, classes and objects that extends the C++ language providing basic functionality to interact with the operating system and some standard classes, objects and algorithms that may be commonly needed. They can be divided in different header files.

The C++ library is divided into three groups:

1. C Standars Library: set of functions available is c language
2. iostream Library: object-oriented library
3. STL (Standard Template Library): set of standard class templates