[ASK] Link Piramid about the Link Wheel

I want to asking bout the lik wheel?
what is a long tail keyword?

and every keyword, we must having a single domain or using a page on that domain?
that really make me so confused. Cos it doesn't talk about domain at all. Focusing only at keyword.

Any explanation about Link Piramid?

thx BHW member..

I think this book could answer your question.