A central administrator can control and modify the data in any centralized system. Any modifications, such as adding, removing, or changing data, are conducted by a central authority solely responsible for keeping accurate records. A consensus process is a fault-tolerant method used within computer and blockchain systems to procure agreement across distributed systems or multi-agent networks, such as cryptocurrencies, on a specific data value or a single network configuration. It's handy for keeping track of items, among other things. Proof-of-Work (PoW) is the consensus process used in Blockchains, and it demands the use of processing power to solve a challenging but arbitrary problem in hopes of keeping all network nodes honest.