You write to a quorum of nodes and you read from a quorum of nodes. Latest is determined by a clock. Let's say you wrote to 2 out of 3 nodes, and read from 2

You write to a quorum of nodes and you read from a quorum of nodes. Latest is determined by a clock. Let's say you wrote to 2 out of 3 nodes, and read from 2 out of 3 nodes, one of those 2 you read from is going to have the latest data. This is how consistency works in Cassandra e.g. There are other models, for example by using a consensus protocol.