Every cryptocurrency transaction spends zero or more coins to zero or more recipients. The difference between the amount being spent and the amount being received is the transaction fee (which must be zero or more).
When a miner creates a block proposal, the miner is entitled to specify where all the fees paid by the transactions in that block proposal should be sent. If the proposal results in a valid block that becomes a part of the blockchain, the fee generated will be sent to the specified recipient. If a valid block does not collect all available fees, the amount not collected are permanently destroyed.
Cobo Wallet makes it easy and efficient for the sender to specify how much fee to pay for the miner to complete a block.