InnoDB is a mysql database Storage Engine. The Mysql default Database Storage Engine is MyISAM You don't need to worry about database Storage Engines that much, its how mysql will index your data. It is said that MyISAM is better when you have large amount of data. You need InnoDB if you want foreign key relationship between tables. http://dev.mysql.com/doc/refman/5.1/en/storage-engines.html