Q&A: What is happening here, and what the heck is a nonce?! So this is a representation of a single block, that will end up on the blockchain. Before we get to the nonce in detail, notice that changing any of the data (block number, nonce, content) changes the hash that is generated at the bottom? Now hit the MINE button. Notice that the HASH and the NONCE have changed. WHAT GIVES?! Well also notice, that the first few digits on the hash are now 0000. Always, no matter what the input is, hitting the Mine button will result in the hash being updated, but the first digits will consistently be 0000. This is the concept behind Proof of Work and Mining. When all the data is captured, a Hash is generated from that data. Behind the scenes, a Hash is generated with a bunch of preceeding 0's (the more 0's the harder the it is to figure out) A miners job is to find the NONCE that will correlate to a hash with the specific number of 0s in front of it, as per the puzzle. REmember when we talked about Hashing, about how its easy to determine what the hash is based on an input, but its hard to determine what an output is, based on a hash? This is why mining takes a lot of effort. Essentially miners are literally trying a ton of hashes each second to determine what the nonce will be that satisfies the puzzle. The winner gets a newly minted bitcoin.