I am beginner and I am trying to understand how blender works. My basic idea was to make hole inside object using Boolean Modifier. I put cube, apply boolean, then I put sphere as boolean object. So nothing happens, but when I clicked on EYE icon of sphere I got perfect result. Now I try to export this as .obj (which is my goal) and sphere is visible inside windows 3D object viewer. My goal is to only have cube with hole inside. What am I doing wrong?

[![All objects visible](https://i.stack.imgur.com/ABlbN.png)](https://i.stack.imgur.com/ABlbN.png)

[![Making sphere invisible (I clicked on eye icon)](https://i.stack.imgur.com/kB4Ez.png)](https://i.stack.imgur.com/kB4Ez.png)

[![Windows 3D viewer](https://i.stack.imgur.com/pfNuW.png)](https://i.stack.imgur.com/pfNuW.png)