Blockchain as said earlier on, is a chain of blocks that contains information.
TRANSACTION
First of all two users decide to initiate a transaction by exchanging a unit of value such as digital currency.
BLOCK PRODUCTION
Due to the transactions on going by other users in the blockchain network, the transaction adds to the list of other pending transactions which in turn creates a block.
A HASH IS CREATED
Hash is contained inside a block and is like a fingerprint due to its uniqueness i.e. Every block contains its own hash, which helps to identify the contents on the block such as sender, receiver and number of tokens to be transferred.
It also contains the hash of the previous block which is attached/linked to the new block. Genesis block is the first block in the chain as there’s no preceding block before it.
VERIFICATION
Basically what keeps a blockchain network running are Nodes.
A node, is a computer connected to a cryptocurrency network that interacts with the network by executing certain functions like creating, receiving or sending information. It is a decentralized distributed ledger that records all cryptocurrency transactions and makes the information available to both users.
These nodes evaluate and verifies that everything is still in order before execution of the transaction and a distributed ledger is generated by the node and displayed to both users.