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.
Angkor Wat is a temple like no other, it’s beauty is beyond words, and the mathematics that went into it equally as precise and full of wonder. The same numbers appear again and again at the temple, and you should really see if you can find more about this wondrous place.