Scalable Vector Graphics (SVG) is an XML-based vector image format for two-dimensional graphics with support for interactivity and animation.
They have a lot of advantages:
SVGs have a DOM so it’s easy to attach event handlers and manipulate elements like you would for other HTML block, so is easy to create interactive contents.
They are supported in all major browsers.
For graphics and vector content, the SVG file size is smaller than a normal PNG image.
Example
Tap on the image to reveal the name of each part...