A Transaction Processing System (TPS) is an information system that processes business transactions to ensure customer orders are fulfilled reliably and efficiently. Key features of a TPS include rapid response, reliability through backups and recovery, inflexibility as every transaction is treated equally, and controlled processing through standardized employee roles. To qualify as a TPS, transactions must pass the ACID test - being atomic, consistent, isolated, and durable. TPS systems can use either batch or real-time processing and rely on databases organized in hierarchical, network, or relational structures to accurately store and retrieve transaction data. A transaction processing monitor oversees transactions to ensure they proceed as intended.