1. The configuration files hibernate.cfg.xml and
2. Mapping files *.hbm.xml

are used by the Configuration class to create the SessionFactory which in turn creates the Session instances.

hibernate.cfg.xml

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
<session-factory>
      <property name="hibernate.connection.driver_class">

com.mysql.jdbc.Driver</property>
      <property name="hibernate.connection.url">

jdbc:mysql://localhost/hibernatetutorial</property>
      <property name="hibernate.connection.username">root</property>
      <property name="hibernate.connection.password"></property>
      <property name="hibernate.connection.pool_size">10</property>
      <property name="show_sql">true</property>
      <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
      <property name="hibernate.hbm2ddl.auto">update</property>
      <!-- Mapping files -->
      <mapping resource="sample.hbm.xml"/>
</session-factory>
</hibernate-configuration>

sample.hbm.xml:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
  <class name="roseindia.tutorial.hibernate.Contact" table="CONTACT">
   <id name="id" type="long" column="ID" >
   <generator class="assigned"/>
  </id>

  <property name="firstName">
     <column name="FIRSTNAME" />
  </property>
  <property name="lastName">
    <column name="LASTNAME"/>
  </property>
  <property name="email">
    <column name="EMAIL"/>
  </property>
 </class>
</hibernate-mapping>