With regards to Risk Management, i recently encountered a query on what are mitigation plans and what is Contingency plan ?

Mitigation actions are taken before the Event occurs, to either reduce the impact or decrease the possibility of occurrence. Contingency is to help support what is required to be done in case the event occurs. Usually the Recommended actions from an FMEA are Mitigation actions. They help reduce the RPN number.

As a practical example, Consider driving a Car, having a speed governor, speed indicator, warning beep, following traffic rules, help Mitigate the possibility of an Accident, these set of actions help detect early, reduce the probability of Occurrence or lower the impact severity. They are mitigation actions.   Insuring the Vehicle & taking a personal Accident Insurance will not prevent Accident, they provide contingency funds to support recovery post the Accident event. (Note: Insurance is considered as Risk Transfer)
In any given scenario, both of them are important and required.

In project execution also, we take actions to mitigate identified risks, & at the same time have contingency buffers to absorb cost & schedule over runs.