Difference between Database and a Blockchain

Database

Database represents a data structure comprised of tables, schemas to store user and system information. It provides SQL to Create, Read, Delete and Update its records. DBMS, Database management systems manages a database. Usually Database administrators modifies the sensitive data. A database follows client-server model architecture.

Blockchain

Blockchain represents a chain of blocks analogous to records in database. This chain grows as blocks are added to it during operations. These blocks contains link to previous block using cryptographic hash of address of the block, timestamp and transaction data. A block once added to the blockchain cannot be modified by design. A Blockchain allows decentralized control as is not modifiable thus elliminates any risk of modification of data by people who can access the system.

Following are the important differences between Database and Blockchain.

Sr. No.	Key	Database	Blockchain
1	Data Storage Approach	Database follows centralized storage approach.	Blockchain follows decentralized storage approach.
2	Administration	A Database Administrator is required to manage a database.	No central administrator is required to manage a blockchain.
3	Data Modification	A database record can be modified by anyone who have sufficient access to the system.	Any blockchain user have a copy of the blockchain and modification to the copy will not be reflected on master blockchain as it is non-modifiable.
4	Versions	A database maintains the latest updates only.	A blockchain maintains the current changes as well as previous changes.
5	Preferred For	A database is preferred when data is large in amount and often needs modification.	Blockchain is preferred to store transactional data and is used in bitcoin extensively.