Blockchain visual demo https://andersbrownworth.com/blockchain/
A blockchain is a growing list of records, called blocks, that are linked using cryptography. Each block contains a timestamp, transaction data, and a cryptographic hash of the previous block.
a hash is like a fingerprint, identifying a block and all its content, it is completely unique composed of a bunch of numbers and letters
By design, a blockchain is resistant to modification of its data. This is because once recorded, the data in any given block cannot be altered retroactively without alteration of all subsequent blocks. changing something inside the block causes the hash to change. changing a block will make all following hashes inactive.
