How did money ever happen? What's it mean? What's it for?

Money isn’t an invention.
It isn’t even a discovery.

It’s intrinsic to the human species. It’s how we keep track of debts with strangers, and cooperate across genetic boundaries - something no other species can do.

Money is a human invention.

Money is a symbol of what others in your society owe you, or your claim on particular amounts of the society's resources.
How money and other financial claims... are created, sold and bought is... . ...[C]laims ...a lot of economics is (or should be) about those.

Money is a wonderful thing. It started out in human history as hard currency, generally gold or silver. These are commodities that are deemed to have intrinsic value but also act as a means of abstractly representing wealth accumulated out of other real commodities. Relatively little hard currency ever circulated freely in the preindustrial world. In that world, most wealth was actual, existing in the form of land, palaces, fleets of boats, bolts of cloth, barrels of grain, standing timber, herds of cattle, and so forth. These were generally things that could be traded, and exchanges of these items were often facilitated through the medium of gold or silver, hence the term "medium of exchange." [The] hard currency could also be acquired by theft or plunder, though that did not necessarily affect its value. Note that the value of [the] hard currency is transcultural. Gold and silver had high value to the Europeans, the Chinese of the Sung dynasty, the Inca, the Aztecs, the ancient Egyptians, and the California Forty-niners.
The industrial experiment took the idea of currency (money) to the next level of abstraction—as hard currency can represent actual goods, so paper currency can represent hard currency and actual goods. As trade increased and took place over ever-greater distances, paper promises to pay hard currency began to steadily take the place of the hard stuff itself, which was cumbersome, hard to lug around in large quantities, and subject to theft in transit. So, to streamline these trades, all kinds of certificates were used as equivalents to hard currency: individual IOUs, bills of lading, letters of credit from rich people, [and] promissory notes issued by guilds. In time, the use of paper certificates became… more normative and conventionalized. Protocols of exchange were established. Institutions were created to process them. This process of managing monetary affairs—of wealth abstracted in [a] paper—was called finance.

We allocate a great portion of our physical, emotional, and mental energy to getting, keeping, and spending money - but how many of us really know what money is or where it comes from? Money is created when banks lend it into existence.

Money talk tends to be confusing. When people talk money, they usually think “wealth”, “costs”, “profit”, “income”, “gold”, “greed”, “time” (as in “time is money”), or something like that. In everyday discourse money symbolises capitalism, for better or worse: money as the life or evil force of the economy. As sings to us in the classical musical Cabaret: “Money makes the world go round… ”. The tune resonates when people exclaim “money” in response to the question what they are after in life, or when they say that everything people do ultimately revolves around money. All this talk is clear enough. The confusion enters when we observe the very same people who are so enthused about money, stubbornly suppress any reference to money when it comes to goods like the love for their partner, parents and children, friendship, science (truth!) and art (beauty!).

Clever though be the many thoughts expressed by mouth or pen about the invention of money and its enormous value as a civiliser, against such praises should be set the curse to which it has always been doomed in song and legend. If gold here figures as the demon strangling manhood's innocence, our greatest poet shews at last the goblin's game of paper money. The Nibelung's fateful ring become a pocket-book, might well complete the eerie picture of the spectral world-controller. By the advocates of our Progressive Civilisation this rulership is indeed regarded as a spiritual, nay, a moral power; for vanished Faith is now replaced by "Credit," that fiction of our mutual honesty kept upright by the most elaborate safeguards against loss and trickery. What comes to pass beneath the benedictions of this Credit we now are witnessing, and seem inclined to lay all blame upon the Jews. They certainly are virtuosi in an art which we but bungle: only, the coinage of money out of nil was invented by our Civilisation itself; or if the Jews are blamable for that, it is because our entire civilisation is a barbaro-judaic medley, in nowise a Christian creation.

Money is the universal, self-constituted value of all things. Hence it has robbed the whole world... of its proper value. Money is the alienated essence of man's labour and life, and this alien essence dominates him as he worships it.

Anthropologically, money should be defined as a semantic system, broadly similar to language; writing, or weights and measures. These systems differ mainly in the purposes served and the signs employed. Language and writing serve the purpose of the communication of ideas, weights and measures that of quantitative physical relationship. As to signs, language uses oral sounds; writing employs ideograms or visual characters; weights and measures, on the other hand, use physical objects as the basis of symbols.
Money resembles, but also differs from, each of these. It serves several ends, which are traditionally described as means of payment; standard of value or money of account; store of wealth; and medium of exchange.

So you think that money is the root of all evil. Have you ever asked what is the root of all money?

Money is the password, and all doors, which are closed to the man of lesser means, fly open to those whom Plutus favors. The invention of money, which has no other usefulness (or at least it should not have any) except for the commercial exchange of the products of man's industry, now serves all that is physically good among men. Especially after money was represented by metal, it has produced avarice which, finally, without indulgence, but by its mere possession, and even with the resolution (of the stingy) not to spend it, still contains a power which people believe can sufficiently compensate for the lack of any other power.

Money had no name of course. And if it did have a name, it would no longer be money. What gave money its true meaning was its dark-night namelessness, its breathtaking interchangeability.

Because in the modern world money does not represent value, Mr. Tighe — money represents debt. And the more debt that is created in the world, the more money there is.