It represents the smallest fraction of 1 bitcoin you can use as an amount in a transaction, so they are the smallest (indivisible) units.
It's not really an important distinction, but maybe someone will find the history interesting.
http://groups.csail.mit.edu/mac/classes/6.805/articles/money...
(and OP seems factually correct: Satoshi was the inventor of Bitcoin).
Proof-of-work schemes like hashcash and bitgold are much closer to hitting on the central ideas that led to Bitcoin. It's like crediting Democritus with atomic theory -- yes, he's talking about the same thing, but in such a way that the final realization is so different as to be unrecognizable.
And it's not really a decimal; it's more properly "1 bitcoin" in the technical sense. 1BTC was later defined to be equal to 10^8 Satoshis because that seemed like a useful amount of money to track exchange rates for (though now it's about 10^4 too high.)
I'm sure OP knows this, I'm just being pedantic.
Buterin couldn't possibly have made it more complicated.
The surprising part for me was that, as a corollary to that, wallets with less than that amount have bitcoin in them which is potentially permanently removed from the total supply of BTC.
a lot of trading is quoted in satoshis instead of "x thousandth fractions of a bitcoin"
That being said, I also had a great laugh reading the article when it came to "200,000 satoshis". Although I totally believe her - it's hard to earn significant amounts of BTC via mining today without investing huge amounts of money and dealing with constricted ASIC supplies, so you need to have time and cash to blow at it. But she shouldn't have mentioned that number in the context of "yeah, our mining ops suddenly started to generate huge returns".
Most of the exchanges shut down their chat rooms but thats where it is mostly said, and other real time trading arenas where people talk. People say 200k/sat while reading .000200000 btc
but a satoshi also works in other quotes where other cryptocurrencies are the base unit as well. In an XMR/ETH market, the XMR would be quoted in X eth-sat or ethereum satoshis.
The GUIs use a variety of different metric base units and there is no agreement on the GUIs, that has nothing to do with the terms people use in speech, as they don't say "x thousandth of a bitcoin"