Types of Templates in WPF

1. Control Template

   This template specifies the appearance of a Control; if a control does not have a Control Template, the Control will not appear in your application.
   For Example - When you will add the template defines as below to your application as a resource then all the buttons in the application will appear as ellipses but will still function as buttons.

   
   <Style TargetType="Button">
    <!--Set to true to not get any properties from the themes-->
    <Setter Property="OverridesDefaultStyle" Value="True"/>
    <Setter Property="Template">
    <Setter.Value>
    <ControlTemplate TargetType="Button">
    <Grid>
    <Ellipse Fill="{TemplateBinding Background}"/>
    <ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center"/>
    </Grid>
    </ControlTemplate>
    </Setter.Value>
    </Setter>
   </Style>
   
   

2. Data Template

   This template specifies a group of characteristics for how data should be displayed. This template is particularly useful when you are binding an ItemsControl such as a ListBox to an entire collection.
   For Example – The Template defined as below, is used to display the items of a ListBox. The data template contains TextBlock controls that bind to the FirstName, LastName, and Address properties.

   
   >Grid>
    >Grid.Resources>
    >src:Customers x:Key="customers"/>
    >/Grid.Resources>
    >ListBox ItemsSource="{StaticResource customers}" Width="350" Margin="0,5,0,10">
    >ListBox.ItemTemplate>
    >DataTemplate>
    >StackPanel Orientation="Horizontal">
    >TextBlock Padding="5,0,5,0"
    Text="{Binding FirstName}" />
    >TextBlock Text="{Binding LastName}" />
    >TextBlock Text=", " />
    >TextBlock Text="{Binding Address}" />
    >/StackPanel>
    >/DataTemplate>
    >/ListBox.ItemTemplate>
    >/ListBox>
   >/Grid>