This process was introduced in the PMBOK Guide Edition 6. It is the only process in the Executing Process Group. Below is the PG-KA mapping,

As the name goes, this is the process where the project team will implement agreed upon risk response plans if a risk were to materialize. Note that this process is performed throughout the life of the project as and when a risk materializes.
One of the key problems with risk management is the fact that project teams spend a lot of time and effort in identifying risks, analyzing them and developing risk responses as well as documenting them in the risk register but take significantly less action when it comes to managing risks. It could have been this very reasons that this process was introduced
The inputs, tools and techniques and outputs of this process are nothing that you haven’t already studied so far
Check more articles on Risk Management