> what the heck is blockchain?

Blockchain in Indonesia was popularized in 2017 by Indodax, named Bitcoin VIP. Since then, the Bitcoin had a amazing growth until finally ethereium was born. In ethereium we can create smart contract. 

Blockchain is a decentralized database that records transactions, maintained across a network of computers, or called as `nodes`.

In blockchain, one database can be chaned to one or more computers (nodes) across the world. These computers called as validators. 

Blockchain itself is impossible to hack, why? because the hacker needs to hack 50%+1% of the data across the nodes in the database.