En technology blockchain, a block is a concept thought to optimize the validation process of the transactions that are carried out.
On the blockchain of Bitcoin each block is generated through the system Proof of Work (PoW), when a computer (or a pool of them) solves the problem or riddle automatically posed by the network.
Bitcoin has dozens of transactions per second. Validating each of these operations individually would be completely unfeasible and would be a long and tedious process.
So the creation of the blocks was devised, through the bitcoin mining, which allow to reference all the information of a block through a hash and make it more manageable and therefore more efficient.
The fundamental structure of a block is a header with data from the previous block and some data on the transactions that users have made. It also adds other data such as timestamp and nuncio.
With all transactions, a central substructure is generated, called merkle tree, which supposes a summary of all the transactions contained in the block, resulting in a Merkle Root, which is what is added in the block to reference all transactions.
As a recurring analogy, the blockchain usually resembles the concept Ledger (ledger or accounting).
Following this similarity, if a blockchain network is a general ledger, each block would be each of the pages that form it and where all the transactions made within the network are recorded.
These blocks usually have different additional conditions. The maximum size of each block is set. Which can depend on the blockchain structure and is also established how often a new block is created. Here we leave you as an example Bitcoin and three of its most important forks:
- Bitcoin (BTC): 1MB blocks every 10 minutes.
- The fork Bitcoin Cash (BCH): 8MB blocks every 10 minutes
- Bitcoin Gold (BTG): 1MB blocks every 10 minutes
- Bitcoin Private (BTCP): 2MB blocks every 2.5 minutes