H/s, MH/s, GH/s, TH/s, PH/s
H/s - Hashes per second.
Hashes per second represent the number of Bitcoin mining computations performed in one second, referred to as hash rate. This is used as a measure of Bitcoin mining performance.
1 GH/s is 1,000,000,000 hashes per second.
1 TH/s is 1,000,000,000,000 hashes per second = GH/s * 1000
1 PH/s is 1,000,000,000,000,000 hashes per second.