What does path mean?

See more:

XAML

WPF

I have the code in xaml

<Grid>
                <TextBlock Text="{Binding Title}" Foreground="White" Margin="15 0 0 0" />
                <Path Width="12" 
                      Height="12" 
                      Fill="White" 
                      HorizontalAlignment="Left">
                    <Path.Data>
                        <Binding Path="ActualMarkerGeometry"
                             RelativeSource="{RelativeSource AncestorType=telerik:LegendItemControl}">
                        </Binding>
                    </Path.Data>
                </Path>
            </Grid>

It draws a square like this.

My questions are I thought it is supposed to use the code RectangleGeometry like this

<Path.Data>
    <RectangleGeometry Rect="50,50,25,25" />
  </Path.Data> 

But it is not. Why?

Secondary question:
The squares are on the left of the text, if I want to place them on the right, how to change the code?

What I have tried:

microsift docs uses

rectanglegeometry

.