Vector graphics are a great way to build images, maps or even UI elements such as buttons or user controls. The idea is that the layout of the image is based on scale. So, when the image is resized or by some other means transformed, the image itself won't suffer from distortions such as pixilation and blurriness. This makes moving from various screen sizes, for instance from a 21" desktop widescreen monitor to a 4" mobile phone screen, more of a smooth process. The backbone of the XAML UI layer is based on vector graphics for these very reasons.