Sample Magento config.xml showing how models are defined

config.xml

<config>
    <modules>
        <!-- omitted for brevity -->
    </modules>
    <global>
        <models>
            <magentostudy_news>
                <class>Magentostudy_News_Model</class>
                <resourceModel>news_resource</resourceModel> <!-- Resource model name -->
            </magentostudy_news>
            <news_resource>
                <class>Magentostudy_News_Model_Resource</class> <!-- Class name specifies the model prefix -->
                <entities>
                    <news>
                        <table>magentostudy_news</table> <!-- DB table name -->
                    </news>
                </entities>
            </news_resource>
        </models>
      <!-- Other content omitted for brevity -->
    </global>
  </config>