This term is used in two ways in Ethereum. Usually, there is a limit to the total gas spent on transactions contained within a block. By limiting the gas used in every block, managing the growth of Ethereum blockchain and the cost of operating a node or miner becomes easier. Collectively, miners can increase or reduce Ethereum’s block gas limit to a certain range.
Theoretically, increasing the limit would enable an Ethereum network to process many transactions per second. Therefore, when the transactions begin to pile up, you will often hear the miner’s discussions signaling for the higher gas limits.