A good article.
In fact, it directly answers a question a Reg reader posted a a few weeks back in response to the article https://www.theregister.co.uk/2017/02/17/machine_learning_graphical_eye_candy/ (The article featured images of graphs by Graphcore, but so complex they resemble slices of brain more than they do a road network)
The reader asked "What does 'graph' mean in this context?" and this article answers it well.
Images are important. I remember as a child and seeing images that represented topology - a teacup being topologically similar to a doughnut, a teapot being similar to a figure-of-eight pretzel. Wow, I thought, this is maths? Cool! I thought maths was just boring numbers!