A MySQL database creates a number of different data files in the mysql data directory (typically
/var/lib/mysql). The following are the differences between the data files created:
I believe these files are created for both MyISAM and InnoDB table types because the MySQL documentation references these types with respect to MyISAM and I definitely see them on my InnoDB tables.
I couldn’t find this information directly in the MySQL documentation and google wasn’t much help either so hopefully this post will save someone else some search effort.