need explanation

Hi am having a c pgm. It has the include files (unistd.h,sys/types.h,win.h,scr.h,curses.h,stdarg.h and color.h). I don't know the purpose of these include files. will u plz explain me.

These are header files, google will reveal the purpose and the source code for each one of them, here's the color.h for example.