It was a header that was available in old Borland compilers. Used strictly for graphics in MS-Dos apps. You are at least 7 operating systems, 16 bits, 20 years and untold compiler versions removed from using it.
Yes, I know that <graphics.h> is gone. I am new to C/C++ and my knowledge is confined to the computer graphics being taught to us in college.
Is there some way I can use graphics.h in CodeLite to study the programs?
The similar level of abstraction in C can be easily reached with SDL You will want SDL_Surface to put points of Bresenham to.
I'd also recommend ClanLib for use with C++, as more convenient to start with.
Both libraries are cross-platform (and can use OpenGL as engine)