Blockchain is a public verifiable and tamperproof ledger of transactions. Public means anyone can look at the transactions by knowing the address of where the transaction originated from or simply looking through the ledger. Verifiable -meaning anyone can compare the transactions with others to make sure they are accurate. You can also verify the transactions using scanners/explorers such as etherscan.io, blockchain.com and bscscan.com. Tamperproof because a network of computers secures the ledger because there are so many copies that you can’t make changes unless you manage to control 51% of the network. Ledger – a list of every single transaction that has ever occurred.
Its called Blockchain because as transaction are completed, they are added to the public ledger and this ledger is stored in blocks of data. Think of each block of data as a mobile home that resides in a neighborhood (network) that is filled with data.
The data (house) consist of 3 types of information.
1 -The transaction data,
2- the address, to determine which data belongs to who
3- the address of the neighbor (the link for the CHAIN hence BLOCK-CHAIN).
A data’s(house) address is determined by its content. If data that is inside the house is changed the address of the home changes. What this does is alert the neighbor that something has changed. Basically, if data in the block has changed the neighbor is alerted of this change (via the LINK) and if it is not confirmed by a consensus (multiple neighbors in the network) they kick out the bad data. Essentially keeping the neighborhood (network) secure.
Who puts this data in the blocks? A network of computer programs that crypto miners run on.