(Quick Reference)
                Domain Class Usage
A domain class fulfills the M in the Model View Controller (MVC) pattern and represents a persistent entity that is mapped onto an underlying database table. In Grails a domain is a class that lives in the 
grails-app/domain directory. A domain class can be created with the 
create-domain-class command:
grails create-domain-class org.bookstore.Book
or with your favourite IDE or text editor.
package org.bookstoreclass Book {
    String title
    Date releaseDate
    Author author
}The class name, by default, is mapped to the table name in lower case and separated by underscores instead of camel case so a domain class named 
BookStore by default would map to a table named 
book_store.  Each property maps to individual columns.
One limitation of the default table naming scheme is that it is problematic to have 2 domain classes with the same name, even if they are defined to be in separate packages.  For example, 
com.bookstore.BookStore and 
com.publishing.utility.BookStore would each map to a table named 
book_store.  If the 2 classes are defined in the application this problem can be managed by giving the classes different names or by providing a specific table name for one or both of the classes that deviates from the default (see the 
ORM DSL section of the user guide for more details).  If one or both of the domain classes is provided by a plugin the application author may not have access to those options.  To help manage a situation like that, GORM may be configured to prefix table names with plugin names by default.  For example, if the 
com.publishing.utility.BookStore domain class is provided by a plugin named 
PublishingUtilities, the default table name could be 
publishing_utilities_book_store.  To enable that behavior the 
grails.gorm.table.prefix.enabled config property must be set to true.  Example:
// grails-app/conf/application.groovygrails.gorm.table.prefix.enabled = true
Refer to the 
configuration section of more details on defining configuration options.
Refer to the user guide section on 
GORM for more information.