>[!tip] You Can't Spell Power Without PoW Proof of Work (PoW) is a key design principle behind blockchain's [[Immutability|immutability]] --> computers hard at work check and validate transactions before finally adding them to a [[Bitcoin Anatomy#Block|block]]. At a high level, the purpose of PoW is to allow for a _provable_ change of asset ownership between _untrusted_ parties. In this process, the amount of work required is set by the [[Difficulty|difficulty]] algorithm. The actual Proof of Work is accomplished by harnessing computing power in a process colloquially referred to as "[[Mining|mining]]", where network [[Bitcoin Anatomy#Nodes|nodes]] compete for Bitcoin rewards by spending power to protect the integrity of the Bitcoin blockchain. Because it creates a computationally expensive, rewards-based competition, PoW systematically disincentivizes dishonest nodes. PoW might also be considered a computational method for redundancy which makes it fault tolerant. For this reason, Nakamoto-style PoW is lauded as a solution to the long-standing [[Byzantine Generals Problem|Byzantine Generals Problem]] in distributed computing.