GAS Coin
GAS is the currency used in the NEO network. It is also known as NEO GAS. It was created with the intention of being used to control the NEO network including the management rights to modify the network. The blockchain technology used by the NEO network is designed so that every time a smart contract is executed, a bookkeeping must be done. This action is then verified by the blockchain technology.
Currently, transactions on NEO are free. However, this is set to change.
GAS is the currency that transactions on the NEO network will be paid for. Eventually, claiming GAS will incur a cost in the future. Claiming GAS daily will incur higher fees and thus become more expensive. This was done in order to limit the number of Gas coins in circulation.