There's a lot of redundancy they talk about in the computing; how does that reconcile to a single output eg. where it funnels down to a discrete actuator? And

There's a lot of redundancy they talk about in the computing; how does that reconcile to a single output eg. where it funnels down to a discrete actuator? And are the decisioning systems (eg. which track/decide which of the four computers to trust) and actuator itself (and surface/component it controls) engineered to a higher standard to mitigate the reduced redundancy available at the "edge" of the system?