The server and hosting management software cPanel uses a standard structure for naming databases in a process known as database mapping. When you want to allow a script to access data in your databases, or to create new tables with which to store new data, your username, password and database name are all required. Without this information, your script will not work.
When you install scripts to your website that require database access to store settings and other data, you must edit a file to allow access for the script to your database. For example, the file "wp_config.php" contains configuration options when installing the blogging script WordPress. When your host uses cPanel, the name of the database includes a prefix and the specific name of your database, which either you assigned or was automatically assigned by a script.
By default, the cPanel database prefix is the same as the account username that the database is on. For example, if your username is "JohnSmith," your database will begin with "JohnSmith_", followed by the individual database name. This naming structure allows you to differentiate between multiple databases on a single account. Your host can accommodate multiple databases on the same server that may otherwise have the same name with the username prefix.
Hosts can remove the prefix option from database names. If your host does this, you will not use any prefix with your database names when creating or modifying scripts. Note that servers with multiple databases may run into issues where multiple customers attempt to make databases with the same name. This will then force you to use a unique name.
If your website is hosted on a Linux or Unix server, database prefixes and names are case-sensitive. Your website will display a "Cannot Connect to Database" error if you do not use the correct capitalization in your prefix. CPanel allows for usernames of up to 16-characters long. MySQL only allows database usernames to be 16 characters long. If your username is the maximum length, you will not be able to create a database if the account prefix is enabled.