NEO sometimes referred to as China’s Ethereum was founded as AntShares (ANS) by Da Hongei in 2014.
GAS is a dividend that NEO holders get for holding NEO. GAS dividends also accumulate as users pay in GAS to deploy and run smart contracts on the NEO platform.
On 2/17/2018 NEO was priced at $135 and GAS at $48.
How does NEO accumulate
The GAS dividend amount decreases about 10% each year. In year one, you accumulated 0.5 GAS per 1,000 NEO coins held. You can find out the latest amounts in the neotogas.com website.
GAS is only paid if you hold NEO in your private wallet, or if you hold NEO on the Binance exchange. Binance makes monthly gas payouts.
GAS can be traded on cryptocurrency exchanges just like NEO. App providers on the NEO network need to either buy GAS or buy NEO to use the GAS dividend to pay for resources on the NEO network.
From the NEO Reddit page: