Svg Vs Render. SVG format allows designers to save static or animated images. One extremely basic way to answer it is use canvas when you cannot use svg where cannot might mean animating thousands of objects manipulating each pixel individually etc.
Those SVG DOM references mean that some of the footwork of dealing with the things you draw is done for you. SVG formats are supported by modern browsers and are future-proof. Designers can create simple SVG renderings in a code or text editor as well as export complex graphics from Adobe Illustrator or Sketch.
How to choose.
Canvas is rendered pixel by pixel. SVG format allows designers to save static or animated images. Vector format renders well at any size. Ability to create simple SVG renders in a code or text editor.