A brief introduction to MySQL binary log
Accroding to the mysql manual, the binary log( also known as binlog) is a very powerful feature that enables the recording of "events" that describe database changes. Those changes could be table modification or data change, and may also contain some statements which may potentially made changes such as
DELETE which no matched items.
This kind of feature enables mysql in replication from master to slave servers by sending events contained in binlogs, and also data recovery. Except for that, it could also be used in CDC(change-data-capture) since it's event based, an example usage could be found in the cdc-component in Eventuate™.