Prefixes are bound to namespace URIs by attaching an xmlns:prefix
attribute to the prefixed element or one of its ancestors.
<svg:svg xmlns:svg="http://www.w3.org/2000/svg"
width="12cm" height="10cm">
<svg:ellipse rx="110" ry="130" />
<svg:rect x="4cm" y="1cm" width="3cm" height="6cm" />
</svg:svg>
Bindings have scope within the element where they're declared.
An SVG processor recognizes all three of these elements as SVG elements because they all have prefixes bound to the particular URI defined by the SVG specification.