Difference
You might want to subtract one object from another. Here is how you would subtract a cylinder from a cube:
- Start with a cube
- Add a Cylinder Mesh by pressing SHIFT+A. You can adjust the size on the left side:
- Select the cylinder and then SHIFT+click on the cube

- Navigate to Modifiers (the wrench)
- Click on Add Modifiers and select Boolean
- Select Difference

- Set the Object to Cylinder:

- Select Apply

- Select the cylinder

- Press X to delete

- Here is the finished cube:





