[development] How does the views module affect taxonomy term pages?

The views module provides a way to redefine how the taxonomy term pages appear. How is this accomplished without patching the taxonomy module? Is there a hook I don't know about, or does the views module simply override the $menu entry? I have looked briefly through the code in both modules, but the interaction is not clear to me. Both modules are complex. However it works, it's a neat trick. I would like to borrow it. Nic Ivy