Definition of a Block in Bitcoin
What is a block in the Bitcoin Blockchain?
A block in Bitcoin or on a blockchain is a group of transactions bundled together that will be placed on the blockchain as public record. Several of these blocks linked together is a blockchain. On the Bitcoin network, every 10 minutes a block is confirmed by miners and is officially added to the growing blockchain. These blocks are counted sequentially from 0, the genesis block to the last one that was confirmed by the miners. Each block is counted sequentially and difference between the last one that has been confirmed and the genesis is considered the block height.
Bitcoin uses a Proof of Work algorithm. This type of algorithm uses computing power to verify that transactions are valid before officially placing them on the blockchain. To verify a block the computers try to solve a cryptography puzzle and the miner that completes the puzzel will receive a block reward. The more computing power a network has the more secure the cryptocurreny is. This is due to the increasingly difficulty of being able to change the public ledger.