From my research about blockchain and bitcoin
Blackchain is a chain of transactions that don't require a third party
It involves opening ledger where all the transactions are centralised and controlled by authorities.
When transactions are made in Blockchain everyone can see  the transaction where the miners will validate the key of the transaction.
The record transactions is linked chronological using cryptography
Why bitcoin is digital currency that is decentralised with recorded transactions without any authority, bank or government controlling it.
My question is how can a bitcoin digital currency transactions will be recorded when no authority, government or bank controlling it?
I appreciate for the reply.