I am studying List Definition in sharepoint 2010.I have two files one schema.xml and another elements.xml
elements.xml
<ContentType ID="0x0101005CF0DB5B6075417a8664EFD23835C831"
Name= "SCORM Content type"
Group="Solutions" V2ListTemplateName="doclib" BaseType="0x0101"
Description="This is the Content type for SCORM Library."
Version="0">
<FieldRefs>
<FieldRef Name="CourseName" ID="{B0884BE9-EE9D-4ae0-97E7-67AA0902A7FA}" />
</FieldRefs>
</ContentType>
<ListTemplate
Name="doclib"
Type="1116"
BaseType="1"
OnQuickLaunch="FALSE"
SecurityBits="11"
Sequence="110"
DisplayName="SCORM Library"
Description="Library to store SCORM courses."
Image="/_layouts/images/itdl.png"
NewPage= "SL/Pages/XSLnew.aspx"
Category="Libraries"
DocumentTemplate="101"/>
Schema.xml
<ContentTypes>
<ContentTypeRef ID="0x0101005CF0DB5B6075417a8664EFD23835C831">
<Folder TargetName="Forms/Document" />
</ContentTypeRef>
<ContentTypeRef ID="0x0120" />
</ContentTypes>
<Fields>
<Field ID="{B0884BE9-EE9D-4ae0-97E7-67AA0902A7FA}" Type="Text" Name="CourseName" DisplaceOnUpgrade="TRUE" DisplayName="Course Name" XName="TemplateUrl" Filterable="TRUE" Sortable="TRUE" Hidden="FALSE" FromBaseType="TRUE" PITarget="mso-infoPathSolution" PIAttribute="href" SourceID="http://schemas.microsoft.com/sharepoint/v3" StaticName="CourseName"/>
</Field>
</Fields>
why we are adding ContentTypeRef? why its ID is 0x0120?why Type="1116" in ListTemplate?