Final Fantasy 12 IHOP - Out of Jail

Y'know, a lot of the yammering I've been doing about Final Fantasy 12 has been related to the game mechanics, not so much the plot. That's because so far the plot has shown up in short little bursts, while the game mechanics have been easy to alt-tab away from (EMULATION FOREVERRRR) and type up a little derp in my .txt file. However, before we're formally introduced to what it is, I want to muse on the nature of Magicite. What is it? What is its purpose?
( Warning: Long, also stupid. )

Okay. For now I save, have some food and rest... and when I come back: The Chickensphere Waits.