It’s a variant of XML (eXtensible Markup Language), which is like human readable binary. It describes images geometrically.
This is to be contrasted with Raster Graphics.
Most, if not all modern graphics are raster graphics. The images we see are all like a painting made on a giant piece of graph paper–here’s a black square, a yellow square, etc.
Raster graphics don’t scale at all well, the new batch of HiDPI screens make the olden low-dpi images look fuzzy.
Remember the old Asteroids arcade game?
Could give sharp graphics before more modern technologies came to eat its lunch
I’ll show you some examples. Let’s open up some of the following files in a source view.
I had to make a quick and dirty layout diagram for a project I worked on, this is the result: