Lately a similar word to money has been bandied about, currency. To differentiate the two, and to learn about money, we'll talk about one of my favorite subjects: beer.
In the US, and I hope everywhere else in the universe where Fours enjoy beer, brewmeisters will put on beer gardens where various purveyors of beer will gather to pour you pints. It is not uncommon for these beer gardens to sell you tickets, and have beers cost four tickets or five tickets so that the vendors don't have to worry about change, and credit cards, etc.
Those tickets are a _currency_. They are the specific medium of exchange for the marketplace that is the beer garden. They have certain properties:
* fungibility: every ticket is the same as every other ticket, and can be exchanged 1 for 1 with each other. Read this for more on fungibility: Half-Fungibility * divisibility: each ticket can be divided the same way, i.e. in half (this is the property that gives us cents and satoshis) * transactions within the marketplace that use them are protected by the rules of the marketplace
Now the beer garden isn't just tickets, it's also beer. And the beer has value, which costs tickets within the beer garden. Outside of the beer garden that beer still has value, and the beer might then be exchanged for other currencies based on that value.
And _that_ value is what money is. And we can say that anything that is a) exchangeable, and b) has some economic value to the exchangers, has a monetary value. And collectively all the things that have monetary value are a part of the superset that is Money.
A currency then is a subset of that, which has the three bulleted properties above. Probably the most significant is the last. Nowadays, the largest marketplace units are nations, or multi-national conglomerates such as the EU. These entities all have issued currencies, which work more or less like those beer garden tickets. Unfortunately some peoples' beer gardens have lousy beer, or are out of beer, and so there's a desire to use other tickets, or tickets that aren't tied to the gardens in the first place.
This latter thing is what cryptocurrencies are. Their desirability, and utility are very much correlated to how the marketplaces will respond with respect to that last bullet above. That has yet to be figured out. And that makes their future speculative. And speculation favors those with money to speculate.
And that's why Planet Nine hooks into the existing financial system where it needs to. Not because it's perfect, but because there is no better established solution regardless of how much people would like there to be one.
But Planet Nine wants to poke at these definitions and considerations, and see if, through experiment, we can find additional concepts or implementations that are useful. To jump to that, check out Planet Nine's Experiments With Money.