A hash is a function that converts an input of letters and numbers into an encrypted output of a fixed length. A hash is created using an algorithm and is essential for the operation of a blockchain.
The blockchain contains only validated transactions, which prevents fraudulent transactions and double spending of the cryptocurrency. The resulting encrypted value is a series of numbers and letters that do not resemble the original data, and is called a hash.
Solving the hash to validate the next block is essentially solving a complex mathematical problem, and starts with the data available in the block header. Each block header contains a version number, a timestamp, the hash used in the previous block, the Merkle root hash, the nonce, and the target hash.
The miner focuses on the nonce, a series of numbers. This number is added to the hashed content of the previous block, which is then itself hashed. If this new hash is less than or equal to the target hash, it is accepted as a solution, the miner receives the reward and the block is added to the blockchain.
