A distributed transaction protocol refers to a set of rules and procedures governing the coordination and management of transactions across multiple nodes or databases in a distributed computing environment. These protocols ensure the atomicity, consistency, isolation, and durability (ACID properties) of transactions executed across distributed systems, where data is stored and processed on multiple interconnected nodes. Distributed transaction protocols facilitate the coordination of transactional operations, such as committing or rolling back changes, across distributed resources to maintain data integrity and consistency. Examples of distributed transaction protocols include the Two-Phase Commit (2PC), Three-Phase Commit (3PC), and the Paxos and Raft consensus algorithms, which are essential for ensuring data consistency and reliability in distributed systems. These protocols play a crucial role in enabling applications to perform complex operations involving multiple nodes or databases while preserving the integrity and reliability of the data. s://en.wikipedia.org/wiki/Distributed_transaction