Proof-of-Work (PoW)
Proof-of-work is a consensus mechanism. Cryptocurrency relies on a consensus mechanism (how blockchains function and are trusted by their users).
With the proof-of-work mechanism, miners (the block creators) need to buy appropriate equipment to mine, and mining involves solving a cryptographic puzzle. When a block is successfully mined, miners receive coins as rewards.
Bitcoin and Dogecoin rely on a proof-of-work mechanism.