The fact the #1 comment on this HN submission refers to "something called gas" (as if it was an advanced concept) instead of "fee" is another data point showing the gas metaphor is confusing :)
Also gas is not its own unit. gasPrice is the unit. Or... actually it's not even a unit. A "unit" implies a constant. But it's not constant since each tx can set its own gasPrice.
The more I think about the cycles metaphor the more I love it. Sorry I have zero sympathy for "gas"
Gas is its own unit, decoupled from ETH. Opcodes cost a certain amount of gas to execute [1]. When creating a transaction, a sender sets the maximum amount of gas that they are willing to pay. This is the "gas limit."
I know what gas is. It would be more accurate to call it a unitless number describing the relative resource cost factor of each opcode.
If you define the term gas as a unit then it refers to both a value, and the unit of that value, which is where most of the confusion comes from. The language "1000 gas" could mean either "1000 wei/szabo/whatever of gas" or "1000 gasCost" which are 2 completely different things!
Also gas is not its own unit. gasPrice is the unit. Or... actually it's not even a unit. A "unit" implies a constant. But it's not constant since each tx can set its own gasPrice.
The more I think about the cycles metaphor the more I love it. Sorry I have zero sympathy for "gas"