Hash Rate – A Hash is the mathematical problem the miner’s computer needs to solve. The Hash Rate is the rate at which these problems are being solved. The more miners that join the Bitcoin network, the higher the network Hash Rate is. The Hash Rate can also refer to your miner’s performance.
Today, Bitcoin miners come with different Hash Rates. Miners’ performance is measured in MH/s (Mega hash per second), GH/s (Giga hash per second), TH/s (Terra hash per second) and even PH/s (Peta hash per second).
A hash algorithm turns an arbitrarily-large amount of data into a fixed-length hash. The same hash will always result from the same data, but modifying the data by even one bit will completely change the hash. Like all computer data, hashes are large numbers and are usually written as hexadecimal.
Bitccoin uses the SHA-256 hash algorithm to generate verifiably “random” numbers in a way that requires a predictable amount of CPU effort. Generating a SHA-256 hash with a value less than the current target solves a block and wins you some coins. Each coin uses different software to achieve similar goals.
This is the specific Algorithm used by Bitcoin: https://en.wikipedia.org/wiki/SHA-2