RTO & RPO

This answer comes from SomuG 

RTO – RECOVERY TIME OBJECTIVE

This is how soon you want your system to be up after a disaster. 6 hrs of RTO means the system cannot be down for more than 6 hrs. For example if a disaster strikes at 8:34 AM, RTO 6 hrs means that the system should be up and running by 2:34 PM.

RPO – RECOVERY POINT OBJECTIVE

This determines the currency of the data when you recover from a disaster.   In the above RTO example, RPO of 3 hrs mean that the data cannot be older than 5:34AM (8.34 AM – 3 hrs). In this case copy of clean data needs to be available every 3 hrs ex: starting 12AM,  3AM, 6AM, 9AM…