The Backup Execution Method affects concurrency within the backup itself.

InnoDb Online Backup will begin a transaction before reading from the tables. Because of the InnoDB versioning system this will allow all tables to be read in a consistent state. This method is recommended when backing up InnoDB tables.

Lock all tables will cause all tables within the backup to be locked simultaneously to prevent writing. This will prevent users from writing to the tables during the backup operation and will ensure that the tables are in a consistent state. This option is recommended for MyISAM tables.

Normal Backup will lock each table individually when performing the backup. While this can have less impact on the actions of users during the backup operation, these is a potential for tables to be backed up in an inconsistent state in relation to one another. This method is not recommended unless the risk of inconsistency is minimal.

Online with binlog pos is the same as InnoDb Online Backup but also logs the current position within the binary log.

Complete Backup overrides the table selection made in the Backup Project tab and backs up all tables in the selected schema. This option can be useful when scheduling the backup of a schema that changes regularly.