A Bitcoin hash rate is the measure of how quickly a computer or a network of computers is able to complete a given number of Bitcoin mining operations. This rate is measured in hashes per second. A higher hash rate means that more mining operations can be completed in a given amount of time and thus more Bitcoins can be mined. The hash rate can also be affected by the current difficulty of the Bitcoin network, which is why it is important to keep an eye on the network difficulty as well when assessing the overall hash rate of the network.