MySQL binary log contains records of all changes to a databases—both data & structure—as well as how long each statement took to execute. It logs SQL statements such as CREATE, ALTER, INSERT, UPDATE & DELETE with the exception of SELECT & SHOW which have no effect on the data.

The purpose of binary log is to allow replication whereby data is sent from a one server(master) to another one(slave) as well assisting in certain data recovery operations. Binary logs are stored in binary format, therefore, you have to use mysqlbinlog utility to view its contents.

In most MySQL setups, binary logging is disabled by default, thus you’ll end up with the following error:

MariaDB [(none)]> show binary logs;
ERROR 1381 (HY000): You are not using binary logging
MariaDB [(none)]> show variables like 'log_bin';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_bin       | OFF   |
+---------------+-------+
1 row in set (0.00 sec)

To fix this, you have to enable binary logs by adding log_bin parameter under [mysqld] section in your my.cnf config. file:

log_bin = mysql-bin

Further Reading

1. MySQL Binary Log