What Is Proof-of-Work?

As you learn more about Bitcoin and other cryptocurrencies, you will inevitably hear the term, "Proof-of-Work" (PoW), used in many articles to describe mining... But what does it mean? 

Let's break down what Proof-of-Work is and why it is so important to the security of the Bitcoin network. 

Short definition: Proof-of-Work is a "consensus protocol" (sometimes called a consensus algorithm) used to prevent spam and denial-of-service of service attacks on a network.

Most often, computing power is used to verify work being completed in order to engage with the service, or in this case, the blockchain. 

To consider the concept of Proof-of-Work more broadly, let's use a few non-crypto related examples: 

Security: Have you ever needed to answer a security question that asks you to identify if you are a human by checking boxes of certain pictures before you can submit an online form? 

You are in essence completing a form of work before being able to submit your email or engage with the network. 

To get even broader, the entire economy works on a Proof-of-Work basis. 

Home purchase: In order to buy a house, you must provide a down payment and have a healthy credit history. The down payment and credit history is essentially your proof-of-work to demonstrate to the seller and the bank you are a trustworthy buyer. 

Conceptually, Proof-of-Work is how we operate as humans. We work 40 hours a week... we receive a paycheck. We complete a purchase of a new car... the dealership lets us drive it off the lot. 

In order to receive a reward, we must put in the work. 

Same with Bitcoin mining. 

How does Proof-of-Work function within Bitcoin and other cryptos? 

Proof-of-Work is the consensus protocol used to mine Bitcoin, secure the network, and add blocks to the blockchain.

Miners secure and validate the Bitcoin blockchain network by solving complex computational puzzles. This requires expensive miners, energy, and time. Basically, these miners are being rewarded for their work, hence "Proof-of-Work". 

Yes, that's a lot. If you need a reminder on how Bitcoin mining works, read our article on it by clicking here. You may also watch Binance's video on Proof-of-Work below to better visualize how Bitcoin mining works and learn the little details: 


Proof-of-Work is the most widely used consensus protocol in the crypto world today. However, other cryptos, such as Ethereum 2.0, are moving to "Proof-of-Stake" and other protocols are being created as well. 

We'll cover Proof-of-Stake in another article soon.

Some in the media will criticize PoW as far too energy intensive or slow. 

There's no denying PoW requires a great deal of energy, but there's also no denying it has created the most secure, decentralized, and largest computing network in the world.