Lazy commit is an important feature of NTFS. It allows NTFS to minimize the cost of logging to maintain high performance.
Lazy commit is similar to lazy write. Instead of using resources to mark a transaction as successfully completed as soon as it is performed, the commitment information is cached and written to the log as a background process. If the power source and/or computer system should fail before the commit is logged, NTFS will recheck the transaction to see whether it was successfully completed. If NTFS cannot guarantee that the transaction was completed successfully, it backs out the transaction. No incomplete modifications to the volume are allowed.