WPF中ControlTemplate和DataTemplate的区别

<Window x:Class="WPFTestMe.Window12"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Window12" Height="300" Width="300">
    <Window.Resources>
        <DataTemplate x:Key="ButtonContentTemplate">
            <StackPanel Orientation="Horizontal" Background="Red">
                <Grid Height="8" Width="8" >
                    <Path HorizontalAlignment="Stretch" 
           Margin="0,0,1.8,1.8" 
           VerticalAlignment="Stretch" Stretch="Fill" Stroke="#FF000000" 
           Data="M0.5,5.7 L0.5,0.5 L5.7,0.5"/>
                    <Path HorizontalAlignment="Stretch" 
           Margin="2,3,0,0" 
           VerticalAlignment="Stretch" Stretch="Fill" Stroke="#FFFFFFFF" 
           Data="M3.2,7.5 L7.5,7.5 L7.5,3.5"/>
                    <Path HorizontalAlignment="Stretch" 
           Margin="1.2,1.4,0.7,0.7" 
           VerticalAlignment="Stretch" Fill="#FFFFFFFF" Stretch="Fill" Stroke="#FF000000" 
           Data="M2.5,2.5 L7.5,7.5"/>
                    <Path HorizontalAlignment="Stretch" 
           Margin="1.7,2.0,1,1" 
           VerticalAlignment="Stretch" Stretch="Fill" Stroke="#FF000000" 
           Data="M3,7.5 L7.5,7.5 L7.5,3.5"/>
                    <Path HorizontalAlignment="Stretch" 
           Margin="1,1,1,1" 
           VerticalAlignment="Stretch" Stretch="Fill" Stroke="#FFFFFFFF" 
           Data="M1.5,6.5 L1.5,1 L6.5,1.5"/>
                </Grid>
                <ContentPresenter Content="{Binding}"/>
            </StackPanel>
        </DataTemplate>
        <ControlTemplate TargetType="Button" x:Key="ButtonControlTemplate">
            <Grid>
                <Ellipse Fill="{TemplateBinding Background}"/>
                <ContentPresenter HorizontalAlignment="Center"
              VerticalAlignment="Center"/>
            </Grid>
        </ControlTemplate>
    </Window.Resources>
    <StackPanel>
        <Button ContentTemplate="{StaticResource ButtonContentTemplate}" Content="1"/>
        <Button Template="{StaticResource ButtonControlTemplate}" ContentTemplate="{StaticResource ButtonContentTemplate}" Content="2"/>
        <Button Template="{StaticResource ButtonControlTemplate}" ContentTemplate="{StaticResource ButtonContentTemplate}" Content="3"/>
    </StackPanel>
</Window>