A transaction is a Logical Unit of Work as well as a unit of recovery. The successful control of transactions is of the utmost importance to the correct modification of related information. In this chapter, you learned how to define and control transactions, examined different transaction-management schemes, learned how the recovery process works, and discovered how to correctly code transactions within triggers and stored procedures. You also learned methods for optimizing transactions to improve application performance and got an overview of locking and distributed transactions. Distributed transactions will be discussed further in the next chapter, "Distributed Transaction Processing," and locking will be covered in more detail in Chapter 38.