1
Miners operate equipment to write transactions onto the blockchain using a consensus mechanism called proof of work.
2
Users publish transactions to the network, which miners then collect and assemble into a single block.
3
The coinbase transaction (transaction zero) is created by the miner to pay themselves the block reward (e.g., 12.5 bitcoins) for their work.
4
Choosing a miner at random ensures liveness and allows anyone in the world to participate in mining and get transactions processed.
5
A Sybil attack occurs when a single entity controls more than 51% of the miners, potentially allowing them to censor transactions, create empty blocks, or revert transaction history.