Pollock is the poster boy for art that looks like a bunch of paint blotches. The reason being that his paintings are a bunch of goddamn paint blotches.
But Actually ...
Fun fact: There's software which can tell a real Pollock painting from an elaborate forgery. How the hell is that possible? Because Pollock's work contains fractals: infinitely complex, never-ending mathematical patterns that are specific to his work. While everyone thought he was merely dripping paint everywhere randomly like a drunken contractor you hired on Craigslist, he was in fact creating entire worlds.
This is explained in the above diagram, which we totally understand.
So how do we know the fractals aren't there by accident? Well, the later the Pollock painting, the richer and more complex the patterns, and thus the greater its fractal dimension. And there are even more mysteries hiding in his work. It appears that Pollock took advantage of an area of fluid dynamics scientists have only recently thought to study. This phenomenon is called "coiling," and you've experienced it while dripping honey, except no one gave you millions of dollars afterward. It's when thick fluid falls onto itself in the form of coils, similarly to rope, and creates patterns that can be described by a mathematical equation.
Anyway, in order to control the coiling, Pollock used a rod to drip the paint onto the canvas instead of pouring it straight from the can or using a brush. By mixing paints of various densities and moving his arm at different speeds, he was able to control the patterns that would show up in the final painting. Dude was doing high math and making it look like a stoner playing with finger paint.