Think of tags as like a book index where you find words and which pages they are on, the same principle applies here. Although it's taken a stage further so it might not be the word, but the subject, so for example if you're looking for things to do with fractal gradients for example. A tag may bring back posts with gradient files, as well as posts that discuss gradients, or tutorials about them.
These variations use the formulas for strange attractors. They are mostly normal variations, not blurs, and will produce the actual attractor when used on a single transform by themselves with no affine transforms, as is done with all of the examples shown here.