Identify the various siege weapons used in medieval warfare. How were each employed in sieges?

As Arther Ferrill explains in The Origins of War, the offense-defense inventive cycle is a cycle of warfare ingredients in which mobility, security, and firepower are intertwined in such a way that a change in one requires changes in others (44). I mention this only because I understand the development of siege weapons to counteract the efficiency of castle defense as a perfect example of this cycle. This is very apparent in the evolution of offensive …

…in the castle walls, and then the storming of the fortification would commence. As Bradbury states, it would be a "gross simplification entirely to attribute the change to the development of guns....it is likely that political and social change was more significant" (295). A Follow-on essay that compliments this one as a two-parter is here: Explain the importance of siege warfare in the High Middle Ages. What was the role of the garrison and castellan?