What is Transaction Fee?

Transaction fees are the fees charged to execute a transaction on a blockchain, and are typically charged to the sender. Transaction fees pay for the computational power a network must exert to broadcast and send a transaction. Transaction fees can be paid out through various mechanisms to entities that furnish a blockchain's security and are a key aspect of incentive models for most networks, including Bitcoin and Ethereum. Transaction fees vary with each blockchain and often fluctuate according to the laws of supply and demand.