Let me offer a few definitions and possibly you will have a different question at that point.
As Project Managers, we manage risk. We do so by identifying risks, analyzing them, and then determining mitigation strategies to either avoid or mitigate (reduce) risks.
Building contingencies into our schedules and budgets is one way to manage the risks that we cannot reduce to zero, or to cover risks we may not yet have identified.
Hopefully these definitions will bring some clarity to your question. Feel free to comment and I will respond.