transaction log(A file that records transactional changes occurring in a database, providing a basis for updating a master file and establishing an audit trail)
log sequence number(A unique number assigned to each entry in a transaction log. LSNs are assigned sequentially according to the order in which entries are created)
transaction log file(A file that contains a record of the changes that were made to an Exchange database. All changes to the database are recorded in the transaction log files before they are written into the database files. If a database shuts down unexpectedly, unfinished transactions can be restored by replaying the transaction log files into the database)
