Replication is a critical component of distributed database architecture, influencing data consistency and availability. In a master/slave architecture, writes occur on master nodes and are replicated to slave nodes, with reads executed on master nodes if consistency is required, which leads to inefficiencies as most nodes remain passive. A masterless setup involves executing writes on multiple nodes and requires multiple inter-node communications, resulting in increased latency and reduced throughput. The primary owner model combines elements of both architectures, allowing reads and writes on a primary node, which is replicated across other nodes, similar to a master/slave system, but with every node acting as a primary node, akin to a masterless design. This model attempts to balance consistency and efficiency, addressing the limitations found in the other two designs.