This drawing module can be used either to draw shapes or text on the chart, or even as a standalone drawing tool for HTML pages.
Inside a chart, the chart's renderer object is available as
chart.renderer. To instanciate a new SVG drawing outside Highcharts, you call
new Highcharts.Renderer(parentNode, width, height), where parentNode is the div or container element where you want the drawing to be placed.
The drawing API is documented in detail at /ref#renderer and /ref#element.