What's a 'bachelor cake'?

What's a 'bachelor cake'?

What's the significance of a 'bachelor cake'? I've never noticed it at any of the weddings I've been to, but I recently saw a layout in a bridal magazine that showed the bride and groom cutting it. When is it cut in relation to the actual wedding cake? Does anyone but the groom get a piece of it? Are any of you going to have one?