DR channels can be deployed to run either on premises or in the cloud.
An on-prem deployment is more rigid, requiring a well-defined architecture depending on expected protection and budget. For example, a 1+1 (or mirrored) design is expensive and hard to maintain ― after a significant investment, you may see 50% of your equipment is always idle.
The alternative could be to build a scaled-down version of the main playout system, but that could end up being insufficient when operators actually have to access it for critical operations.
A cloud deployment for DR, however, gives you the flexibility and elasticity needed to meet your requirements as you respond to different circumstances. It also enables you to design a system with a subset of features compared to that of the main channels ― configurations that are sufficient to keep your channels alive and on air.