Re: Converstion in OpenGL
All windowing systems have an API to create windows etc. If you make those calls you will get a window.
In addition where OpenGL is supported there is always a platform specific API to allow 3D OpenGL drawing contexts to be created and associated with the platforms windows.
In addition to this some Operating systems will create a command line style 'console' if you have a program that starts with main. Windows requires a winmain function instead of main if you want to avoid a console. Whether or not you have a console you can still create a 3D graphics window in Windows.
The details of creating a window can be tricky for beginners so to get things started quickly just use GLUT or a similar API to do the windowing and get yourself started quickly on the 3D stuff.