Hash (rate)
The hash rate is the measuring unit of the processing power of the Bitcoin network and refers to the speed at which a computer is completing an operation in the Bitcoin code. A higher hash rate is better when mining as it increases the miner’s opportunity of finding the next block and receiving the reward. When the network reached a hash rate of 10 Th/s, it meant it could make 10 trillion calculations per second.
There are different codes for different speed of hash rate used which are as per below:
1 kH/s is 1,000 hashes per second (sometimes mistakenly written KH/s). (one thousand/ kilo)
1 MH/s is 1,000,000 hashes per second. (one million hash/mega)
1 GH/s is 1,000,000,000 hashes per second. (one billion hash/ giga)
1 TH/s is 1,000,000,000,000 hashes per second. (one trillion/ tera)
1 PH/s is 1,000,000,000,000,000 hashes per second. (one quadrillion/ peta)
1 EH/s is 1,000,000,000,000,000,000 hashes per second. (one quintillion/exa)
In terms of the International system of units (SI), these will be referred to with prefixes as
kilo-, mega-, giga-, tera-, peta-, exa-, each translate to an increase by a factor of one thousand.
Mining capability is measured in the number of attempts to find a block a miner can perform. Each attempt consists of creating a unique block candidate and creating a digest of the block candidate, a hash. Since this is a continuous effort, it is spoken as hashes per second or [H/S].
2 minute video explanation:
https://99bitcoins.com/what-is-bitcoin-hash/
(below text is taken from 99bitcoins)
In order to decide which block of transactions will be entered next to the blockchain, some sort of contest is held between the miners. They all get a riddle to solve, but you can’t actually solve this riddle logically – you have to guess the answer.
Imagine that you are a Bitcoin miner, and each time you want to enter your block into the blockchain and get a reward you would be given a combination lock and would need to guess the combination in order to enter your block. Now let’s say that your computing power or hash/rate is the number of combinations you can guess in a second.
So the more computing power you have the faster you’d guess the combination. Since the Bitcoin network wants to keep the time between blocks created in the blockchain constant, as more miners or computing power are added to the network it will become harder to guess the combination.
Just imagine that as more and more people try to guess the combination you will be given locks with more possible combinations. A hash is just a method used to guess the combination for the lock. It’s used by turning a random large number into a smaller number by taking certain actions. so for example – let’s say that each time you guess the lock’s combination you would randomly pick a large number and take the first, middle and last numbers from it. If this doesn’t work you will randomly pick a different large number and guess again. Of course, the miner’s’ calculations are much more complex but the idea is that you decide on a certain method of action for guessing and execute it until you get the answer.
The SHA-256 or “secure hash algorithm 256”, is just a specific way of hashing. The same way we could have named our previous example for hashing the “99Bitcoins hashing method”. Using hashing helps the Bitcoin network stay immune to alteration and fraud.
ORIGINAL POST ON MY WEBSITE: https://www.eliteblockchaincoalition.com/main-blog/2018/2/2/what-is-hashpower-hashpower-explained