1. The transactions. 2. The mechanism used to determine what 'mining' bitcoins means is defined by the bitcoin client software implementation. In case of bitco

1. The transactions. 2. The mechanism used to determine what 'mining' bitcoins means is defined by the bitcoin client software implementation. In case of bitcoin it is about finding a suitable random number by using brute force. 3. I believe the cartoon is using sahti in comparison to bitcoins or ether or any internal currency used in a public blockchain.