Dear @hamzayousaf you brillintly explained it all. But some questions are still poping in my mind.
- Block is created once it is completed/verified a peer to peer transaction it is distributed, then where the created block is saved?
- What i saw no code in this world is without bugs and vulnerablities how we can say blockchain is uncompromiseable?
Bitcoin blockchain works on the principle of Byzantine fault tolerance, where one miner wins bitcoins by solving a difficult puzzle (Proof of work) while other miners verify that the block the winning miner wants to add to the blockchain has correct information. The only way you can disturb this, is using the 51% principle, where the miner who solves the puzzle deliberately gives incorrect information, and more than 51% of the verifying miners agree with it. But even like that, you won't be disturbing a lot more than one block in the blockchain, due to the very high hash rate required to do that.