This article provides information about the information_schema database in MySQL.
The information_schema database is a virtual database that MySQL uses to store information about your databases and other settings. For example, you can query the information_schema database to obtain information about character sets, statistics, and much more.
Although you can query tables in the information_schema database, you cannot modify them. You also cannot delete the information_schema database.
To see an example of the information_schema database in action, please see this article.
For more information about the information_schema database in MySQL, please visit http://dev.mysql.com/doc/refman/5.5/en/information-schema.html.