A pointy object that runs down the back of many larger animals, including humans. It both serves as the main conduit for nerve impulses in the body and serves as a defence mechanism by threatening to puncture anything that approaches it aggressively.
You must protect it well as there are certain spinestealers which without warning may take it from you to put on a shelf. leaving you defenceless and unable to move. But have no fear a new advancement in Microsoft means you can get a robotic replacement without worry of...too many crashes.