Hash rate is a measure of the total computational power being used by a proof-of-work cryptocurrency network to process transactions in a blockchain. It can also be a measure of how fast a cryptocurrency miner's machines complete these computations.This refers to the number of miners working to verify transactions and the speed at which they can generate hashes in a proof-of-work network.
For miners, a hash rate shows the competitiveness: if their equipment has a lower hash rate than competitors, they won’t win. If they’re working within a network with high hash rates, they can expect to be competing with a larger number of miners.
For investors, a hash rate is a measure of network security/health. The higher the rate, the more difficult it is for someone to hack the network because there are more computers validating transactions. As a result, the higher the price of the cryptocurrency, the higher the hash rate tends to be as more miners seek to gain profit. As the price of the crypto falls, the profit margin shrinks, fewer miners participate and hence the hash rate decreases.
In the long run, hash rates tend to go up over time as increases in profitability drive more miners into the network.