Final answer:
A schedule S is said to be serializable if it is conflict equivalent to some serial schedule, ensuring that it maintains the database's consistency and integrity like a serial schedule.
Step-by-step explanation:
A schedule S is said to be serializable if it is conflict equivalent to some serial schedule S'. In the context of database systems, serializability is a property that ensures that a schedule (or a sequence of transactions) will leave the database in the same state as would a serial schedule. Serial schedules are those where transactions are ordered and executed one after another, without any interleaving actions. If a concurrent or interleaved schedule is conflict equivalent to a serial one, it means that, despite the concurrent execution, the final state of the database will be the same as if the transactions were executed in a serial manner. This is crucial for maintaining the consistency and integrity of a database.