The hash rate is defined as the speed at which a computer can transform any amount of information into letters and numbers of a certain length. This process is called “hash”.
The hash rate is usually calculated in hashes per second (h/s). It can also be expressed as the combined speed of each computer on the network.
The hash rate is a measure used in connection with mining. Mining is the process of recording and verifying the information of data that is collected as a block in the blockchain. To control when blocks are created, users must get their computer to solve a mathematical problem that involves hashing.
Bitcoin Proof of Work Protocol
Proof-of-work puzzles are based on hash functions and form the basis for Bitcoin’s security model. Since the “work” is repeated hash functions, the combined calculations of each Miner in the network to solve these functions are called hash rate.
In general, a higher network hash rate corresponds to a higher security level for a particular blockchain. Bitcoin’s security guarantees assume that no one Miner controls a large part of the hash rate. If they did, they could carry out a 51% attack. A 51% attack is like a “hostile takeover” of a block chain. Since the miners would then have a higher hashrate than the rest of the network combined, an attacker can effectively rewrite the rules of the protocol and double his own previous transactions (double spending). But even in this case, they cannot spend other users’ money, as this is protected by cryptography.