aren’t correctness and consistency the same thing? They are not, and here’s my clarification.
Although correctness and consistency are sometimes used interchangeably, they are not the same thing.
Correctness means your system produces the right answer. If a user transfers $100, their balance reflects exactly that, no matter which node handled the request or what crashed in between.
Consistency means every node sees the same data at the same time. If you write to node A, a read from node B immediately sees that write. This is about visibility and agreement across replicas, not about whether the answer is right.
Fun fact - a system can be consistent but still wrong :) If you replicate a buggy write to all nodes instantly, every node now agrees on bad data. That is perfectly consistent. It is also perfectly incorrect.
So, correctness is your responsibility, while consistency is a property of your replication model. Hope this helps.