I keep hearing people with explore machine asking this question all the time so I decided to make this post only to explain what it is.
SVG stands for the scalable vector graphic. The exact definition is:
SVG is an XML-based vector image format for two-dimensional graphics with support for interactivity and animation. The SVGspecification is an open standard developed by the World Wide Web Consortium (W3C) since 1999. SVG images and their behaviors are defined in XML text files.
It pretty much means that it is computer calculated image and you can resize it however you want without losing the quality of your picture. For example, if you enlarge JPG file, your image can become “pixeleted” and have funny looking squares all over it. It isn’t sharp and pretty much not nice anymore. But if you enlarge SVG, you won’t get any of that. The image appears the same as before you resized it.