What is meant by a transaction in database management?

A transaction in database management refers to a series of operations that must be executed as a single logical unit of work. This means that all operations within the transaction must either complete successfully or, if any one of them fails, all operations are rolled back to maintain data integrity. This concept is fundamental in ensuring database consistency and reliability, particularly in environments where multiple users are accessing and modifying data concurrently.

The significance of transactions lies in the ACID properties they uphold: Atomicity (ensuring complete success or failure), Consistency (ensuring the database remains in a valid state), Isolation (ensuring transactions do not interfere with each other), and Durability (ensuring once a transaction is committed, it remains so even in the case of a system failure). Therefore, option B accurately captures the essence of what a transaction entails in database management contexts.

The other choices describe different aspects of database operations but do not align with the definition of a transaction. Data cleansing operations, methods of presentation, and indexing procedures are all important components of database management but do not encapsulate the transactional process and its requirements for atomic execution and integrity.