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.

Elliptic Sample 17

Elliptic

The most commonly used coordinate systems are rectangular coordinates and polar coordinate. But these aren’t the only possibilities. One of the less common coordinate systems is elliptic coordinates. Although their mathematical application is specialized, they can be used in variations to make interesting flames.