OpenGL文件的区别。h和gl.h / glu.h

I've build an opengl program with my glu and gl header files default included in windows 7 professional edition. Now, I've bought a book that describes OpenGL game development. The author of this book said, I have to include the glew header into my project. After I've done this I got some unresolved external symbol errors.I've build an opengl program with my glu and gl