Proof of work and mining

Going deeper, proof of work is a requirement to define an expensive computer calculation, also called mining, that needs to be performed in order to create a new group of trustless transactions (the so-called block) on a distributed ledger called blockchain .

Mining serves as two purposes:

1. To verify the legitimacy of a transaction, or avoiding the so-called double-spending;
2. To create new digital currencies by rewarding miners for performing the previous task.