STC头文件指的是采用C语言开发STC单片机时所需要的硬件定义文件，对于不同的单片机型号，头文件对应不同，其中主要定义单片机硬件的功能及接口。只有在头文件中做好了定义，才能对应上C语言程序与硬件之间的关系。

在C语言家族程序中，头文件被大量使用。一般而言，每个C++/C程序通常由头文件(header files)和定义文件(definition files)组成。头文件作为一种包含功能函数、数据接口声明的载体文件，用于保存程序的声明(declaration)，而定义文件用于保存程序的实现 (implementation)。

-STC header file refers to the microcontroller using C language development when the STC hardware definition files needed for different MCU model, corresponding to different header files, which define the main function of microcontroller hardware and interfaces. Well only in the header file is defined to correspond to the C programming language and hardware relationships. Family of programs in C language, header files are heavily used. In general, each C++/C programs are usually header file (header files) and the definition file (definition files) form. Header file contains function as a function of carrier file data interface declaration, a statement to save the program (declaration), the definition file used to save the program implementation (implementation).