Hash rate – also known as hash power, is a value that represents a number of times a hash function can be computed per second by a miner or the whole network. This value depends on 2 factors:
The actual computing power of a miner;
The network a miner works in. Difficulty of hash function can be different in different networks.
For example, the hash rate of Nvidia GTX 1060 6GB, one of the most popular GPUs for mining, in Ethereum network is approximately 24 MHash/s. It means that this GPU is able to run hash algorithm approximately 24 million times per second.