SVG Scalable Vector Graphics is an XML-based vector image format for two-dimensional graphics with support for interactivity and animation. Because of its scalable native, especially with very high graphical screens(example: retinal screen for Mac) these days, we need solutions for images or graphics to be display on these screens.
Well these are many ways to resolve these, such as using large image 2x of your current size and scale down to smaller dimension on web, or for icons we use Font-icons. Since SVG was widely used on most modern browsers including IE9, and its pretty lightweight we should make use of it.
How we can use SVG on the web and why we will use it.