difference of freeglut vs glew?

I've recently started learning OpenGL (> 3.3) & I've noticed a lot of examples & tutorials use both freeglut & glew, but don't really explain the difference at all. The best description I've found, after googling & reading ad nauseum, has been this OpenGL Related toolkits and APIs but found it lacking. I've even read the tag info on SO.

As someone really new to OpenGL I'm still trying to get a grasp of the different concepts. I've gotten to the stage of creating a basic program that uses glew, create context (on windows, VS2010), & draw really basic shapes, all without the need for explicitly including freeglut. So I don't understand why I would need it.

So my question then is, what's the difference between:
-freeglut
-glew
-(& glfw)
What can one do that the other can't?

Solution 1:

The OpenGL Extension Wrangler (GLEW) is used to access the modern OpenGL API functions(version 3.2 up to latest version).If we use an ancient version of OpenGL then we can access the OpenGL functions simply including as #include <GL/gl.h>.But in modern OpenGL, the API functions are determined at run time, not compile time. GLEW will handle the run time loading of the OpenGL API.About GLEW see here

GLFW or freeglut will allow us to create a window, and receive mouse and keyboard input in a cross-platform way. OpenGL does not handle window creation or input, so we have to use these library for handling window, keyboard, mouse, joysticks, input and other purpose.

GLFW and freeglut are alternative for us according to our need we can choose any one but GLEW is different from them which is used for run time loading of the OpenGL API.

Solution 2:

I'm using both of them for some work at my university.

GLEW is a "cross-platform open-source C/C++ extension loading library" (from its website), while freeglut is a window manager that replaces the default OpenGL Utility Toolkit (GLUT) library.

So, as you see, both different have different purposes. The point of using freeglut is that it's still maintained, while the default GLUT isn't, so if you want bug fixes and new features you should use it :)