1. Centralization vs. Decentralization
Regular DB: controlled by a single admin (for example, a company stores user data on its server).
Blockchain: a copy of the data is stored by thousands of network participants; no one can unilaterally change everything.
2. Data Mutability
Regular DB: records can be edited or deleted.
Blockchain: data is immutable — every action is permanently recorded, like an entry in a log.
3. Trust
Regular DB: you have to trust the database owner (for example, a bank).
Blockchain: trust is built on mathematics and protocols — the system ensures honesty by itself.
4. Security
Regular DB: server hacking = loss or alteration of data.
Blockchain: hacking one copy is futile because thousands of others will confirm the forgery.
Result:
Blockchain is not just a 'new database'; it is a way to create a system where there is no single point of control and data is protected at the protocol level.